I've always liked hacks and other fangames that allow you to be evil, as it grants a welcome change or pace from the usual "8 gyms, Elite Four, I wanna be the very best" routine that the main games follow religiously. I'm thoroughly enjoying this hack so far, and want to see you do the best you can to see it through! I'll give you a few pointers that you may find will make your hack an even more enjoyable experience.
I noticed that trainers all react the same way after they've been beaten regardless of whether or not I chose to steal their Pokémon. Stealing someone's Pokémon only to have them say "Zubats are weak at first, but become really reliable later." or something like that seems a little weird, don't you think? You should give everyone something different to say depending on whether or not you spare them or steal from them. For instance, if you stole from a young trainer who didn't think you were evil (like you did with the little girl at the beginning, I really liked that), they should react out of complete shock and have contempt for you afterwards, or just treat you like another trainer in a strange uniform if you leave them be. In another case, you could have a character like a police officer or one of the "heroic" characters see you in a more positive light if you choose not to steal from them, or steal from them to have them become tougher and more wary of you the next time you see them.
Then again, you may already have all of this planned for future releases, in which case, nevermind my rambling. Again, great hack so far. I really hope that you'll see this to the end.
One minor thing is the swearing in the game. While I'm not against swearing in and of itself, it feels really strange having familiar characters in a familiar Kanto region behave out of character in this fashion.
Yes, characters having different post-battle dialogue depending on whether you robbed them or not does make for a more dynamic experience and is something that will definitely be implemented in the second beta.
I'm afraid you'll have to stomach the mild swearing, though: Having characters that speak roughly to each other juxtaposed with a traditional Pokémon environment is part of the game's style; part of its intention of playing with, and paying homage to, players' expectations of a Pokémon game. It is meant to feel strange.
For the record, though, language will always be kept strictly PG-13, so you won't have to worry about finding any graphic profanity if that's a concern.