No. You can however use PokéSav, a program which creates Pokémon with whatever stats you desire.
No
I do not believe there is, but i MIGHT be wrong. Sorry :(
Train it as you train all pokemon.
hmm, I'd have to say, yes and no. It all depends on how you look at it. If you are trying to EV train a Pokemon, yes, using Action Replay for exp can make your Pokemon weaker then normal. For normal Play, I'd have to say, its fine. I do it, but I only use the Double Exp after battle.
No, but there are codes to encounter Pokemon at lvl 100 and others to get 999 rare candies. But if you use the rare candies, you won't be able to EV train the way you want. Stick to the right way for the strongest Pokemon.
If you only mean not using action replay, then use pokesav. If you mean no cheats, then I have to say, there is no really quick way of getting your Pokemon to lvl 100. The E4 are your best bet's. If your EV training, then keep EV training until you get to lvl 100. Hope this helped.
Yes, you can
It's pretty obvious... EV train (I suggest EV Training in Defense)...
train them without using rare candy's
94000130 FCFF0000 62101D40 00000000 B2101D40 00000000 00000090 000F423F D2000000 00000000 Have it on my Action Replay DSi ~_^
yes.. you can
of course you can unless the level of the Pokemon is to low to reach 252. just EV train until it wont allow you to give your Pokemon anymore.