Yes, that does make it fair. Because both players become aware of the stage change and actively position themselves in a more advantageous spot. A stage advantage itself is fine on it's own. It's no different than positioning yourself in the bottom platform of battlefield and keeping your opponent above you.
What you said above is true, except for one small condition: What if you DON'T manage to "position yourself in a more advantageous spot?" You're assuming here that, upon seeing an impending stage change, both players would be able to secure an advantageous spot on the battlefield in a very short amount of time. Especially where certain character match-ups are concerned, this would be very, very difficult. Just like the Venom stage has situations that inherently favor one area, so would the Pokemon Stadium stage favor certain areas. Certain characters (Marth comes to mind) would have a much easier time holding certain pieces of ground on Pokemon Stadium than would others; thus, you can't really "claim an advantageous piece of ground" that easily. I can see where you're coming on it being "fair", however, since even if you can't get the spot you want, you WERE technically forewarned.
No, it's because you can predict that the cloud is going to be on the opponent's side before it actually comes out. You can time your recovery to land on the cloud as soon as it comes out by simply paying attention to the time limit above your head.
I agree that you can effectively predict where the cloud is going to be...however, my question to you is, can you predict where YOU will be in the next 5 - 10 seconds of the game? No, you can't. You can certainly TRY your best to "time your recovery"; however, again, you make this sound like a surefire shot - you will NOT be able to land on the cloud every time because, sometimes, the cloud won't be on your side AT ALL. Most characters can't stay in the air long enough to just wait for the cloud to come and save them; fast-falling characters like Fox and Falco especially would be dead long before it reached them. Again, you can "know the situation" all you want - my point is that you can't know where your character will be relative to the cloud at any future point in the game. Thus, luck still plays a strong factor in who gets saved and who gets dumped.
A natural divider in itself is not a game breaking flaw, but one in which the defending character has just as much or more manuverability than the attacking character can be an insurmountable advantage. Lets say that Marth decides to stay right next to the large fin on Venom and he has a percentage lead. In order to approach you'd have to go over the fin. The only problem is that he can attack you as you approach, and very easily. You'd have to go very high to get over both him and the Fin, but then he'd simply move to the other side of the fin and you'd start all over again.
On stages that aren't circular than it is assumed that it is actually possible to catch an opponent. That isn't the case with stages like Hyrule temple and Termina Bay, where it is litterally impossible to catch the opponent because they are faster than you and never actually have to cross your path. On stages like FD and Battlefield they have to eventually turn around and go back, allowing you to intercept them.
In the most extreme cases, it's actually impossible to overcome the stage advantage with certain characters. If you opponent counterpicks Hyrule temple and choses Fox, all he has to do is laser you once and run in circles for the rest of the match. The only vaiable character choice for this situation would be Fox. If you ban Fox, then Falco becomes the only choice, and so on. It's much more effective to ban the stage in this situation.
Alright...I accept the fact that some stages simply aren't built for serious competitive play.
But, the cloud doesn't just happen to be there. You could look up at the timer and predict when it will be out next. Knowing the case is everything. If you know the cloud will be on one side in the next 5 seconds, move the fight to the other side if you want to kill your opponent, or move to the side with the cloud if you're on the defensive. If you haven't noticed the cloud until after you knocked your opponent towards it then it's just your poor usage of the stage, not the stage unfairly benifiting your opponent. If you did know the cloud was going to be there, and you still hit your opponent that way, then you've just willingly given your opponent the stage advantage. That would be no different than jumping onto a platform that's right above Marth. You've practially asked them to use part of the stage against you.
Again, you're right about being able to predict where the cloud will be in the next few seconds of the game. However, as I said before, you CANNOT do the same with your character. If everyone knew exactly where their character would be relative to the cloud at every future point of the game, then everyone would get saved by the cloud, every time (neglecting the possibility of your opponent knocking/spiking you away from it). But it's not that simple. You can certainly TRY to "move the fight to the other side" when you see the cloud moving towards one side, but whether you'll actually succeed or not is another matter. Your explanation makes it sound simple to "switch sides" on the stage with your opponent and manipulate the situation so that it benefits ONLY you. This is absolutely not the case - as I said before, you can always know where the cloud will be, but you can't always know where your character will be relative to that cloud in the next few seconds of a given game. I don't think anyone truly PLANS on being hit away from the cloud, nor do they plan to have their strategy messed up by their opponent. However, these things do happen, constantly and consistently. They happen so often that it can be assumed that luck plays a large part in who gets that cloud - true, skill plays some part as well, like you said, but luck is still undeniably there. The bottom line is this: anyone can predict where that cloud will be - but NO ONE can predict where THEY will be in the next few seconds.
At certain percents and positions that's not always an option. In competative play where money is on the line I think it's best to remove that possibility if possible.
True - items do not mix well with money and competitive play.
So what if a Bomb-omb popped out of no where while you were comboing me and you got killed by it, you shouldn't have attacked me knowing that there was the possibility for something like this to eventually happen.
By the "playing-to-win" theory, I wouldn't have been killed by the Bomb-omb...I would have DIed the hit, teched to the ground, and returned to the fight. If items were integrated effectively into your game, you would constantly be expecting the possibility of a random explosive item like that - much in the same way that you'd be expecting a chance to jump on the Yoshi's story cloud.
Do you see my point here? It's not that the items appear, it's where they spawn and more importantly when they spawn. Neither player can plan for something they have now way of knowing will happen, and it's naturally advantageous to one player over the other. I don't care that the hammer is really easy to avoid, it still shouldn't randomly pop up when money is on the line.
Yes, when money is on the line, it would not be smart to involve items. I still think it would be worth it for Smashers to start experimenting with item-intensive games and start applying their skills to them.
Winning is your first priority in a competative tournament. If you didn't win, you analyze why you didn't win and try to win next time. I believe that items would never fully be integrated in competative play because there's just no way to predict when and where they will appear. I personally believe it would take away depth from the game because it would on occasion lessen the importance of skill in a match. In competative play we want to get rid of as much randomness as possible, in order to emphasize the importance of skill in this game.
Again, if items were integrated, people would learn (I hope) to be ready to DI/grab/dodge/use items as soon as they appeared. In other words, it could very well become second nature. Whether or not they take away from the depth of the game depends not on items in general but on the specific case - if a match degenerated into both players simply charging for all the items and throwing/using them madly, then yes, the depth would be gone. This could be compared to a normal match where characters simply spam smash attacks or powerful B attacks - relatively no depth. However, if both players were using a MIX of item-based combat and standard character based combat, plus advanced techniques, you would get a healthy hybrid of Smash play that would be very, very interesting to watch and probably even more interesting to play. In this case, it would either add depth or keep it the same, as well as make it a tad livelier.
I will say, though, that at this point item-based matches would not work in competitive gaming because they would introduce more luck into the matches than there already is - which, when money's in the question, would not be as fair. In other words, even if you DI every Bomb-omb that blows up on you, it'd still increase your percent and therefore give the other player an advantage.