If I want to modify my game (considered cheating) to make all my zerg units look like puppies they can go screw themselves if they think they're going to ban me. Knowing that they might try, I will not be paying for SC2. I strongly believe in doing whatever the hell I want with a game in single player, anyone who interferes with that will not be too happy.
Its all part of the game.
Everything you can do with mods you can already do thanks to the campaign editor and the in-game cheats.
The biggest difference here is that the in-game editors and cheats don't score you achievements. So why are they using them? For the achievements of course.
Yes. You can make your zerglings look like puppies.
And besides, theres offline mode if you really really want to use the trainer. But the trainer is retarded. Its like giving yourself a handicap. If you really need to worry about your APM, look at it during the replay, not during your actual gameplay. Doesn't help one bit.