Er...couple things: the Klap Trap is not random, and is easily predicted with the help of the timer. It's cycle is just over ten seconds. The bombs are not a constant threat either... if they've already landed, there is nothing random about them. They become a predictable stage hazard - you hit them, they explode. The randomness is a problem when they haven't landed yet - you jump into one, or one falls into your attack etc. with no warning. Keep in mind that no blocks will fall if the top layer is already filled. If you don't attack the blocks, it won't be long before the threat of random bombs goes away, and you're left with only the ones on the stage already, which have no randomness about them.
I've played plenty of matches on Green Greens where neither player unintentionally detonates a bomb. I've also played matches where players get saved twice by falling blocks. I've played plenty of matches where Yoshi's doesn't save anyone, but I've played matches where multiple saves happen. Arguing over frequency isn't going to get anywhere since we don't have hard numbers to back it up.
Let's say Green Greens worked like this: every time you pass over the block space while not in hitstun, it drops a bomb on you. This is how the stage works - it's programmed to react to your passing over the blocks by dropping a bomb on you. You can still airdodge to be unhurt from the explosion. This places limitations on players, and these limitations are what you're complaining about, right? My point is, it's not the randomness that forces these limitations - they would exist even if the stage weren't random, so it's a separate issue.