Ryuu, you're the reason that I come to the kirby boards.
Let me help you out.
The thing is, you're playing computers. I appreciate you don't have anyone to play with, that's fine. But the strategies and thoughts discussed on this forum are assuming you're playing a human. There's a big difference in how computers and humans play. I'll explain this in more detail later.
Really, my advice to you is this. Consider seriously whether you want to get good at this game in the community's eyes. If so, you need to go out and find human players in your area. If you want real experience in the game you need to play people: computer practice isn't getting you there.
If, on the other hand, you're just happy being good against computers that's fine. And you are undeniably good against computers. Do what you're doing if you enjoy it. But this community doesn't appreciate skill against computers: it's only concerned with skill against players. Don't try and give and get advice from this community. The community's goals and yours are different, and that won't change. Instead of looking for approval from the community, just enjoy it socially.
The reason you underrate shielding and dodging is because computers are relentless. They constantly follow you and attack you. They never back off, they don't bait. As such, it is easy to predict when they'll attack. And it's a lot easier to just stick out a hitbox before they'll attack than shield or dodge.
On the other hand, humans bait. They move around. They'll back off if you think you're going to attack. As such, you can't consistently predict when they'll attack. You'll occasionally end up getting it wrong and throw out a move. And when you throw out a move, you have endlag that is punishable. Shielding is a safer option because if you're wrong, you don't have as much endlag.
There's lots of things that computers do that are predictable that humans are not so predictable about. To really appreciate it though, you need to play some good human players.