Editing pokemon sent over from your DS?

[Erikur]

After discovering that my dreamworld nidoran basically didn't have a single decent IV-value i decided i have had enough of the RNG, so I downloaded pokegen, ir-gtsBW and python 2.7. So i basically just want to improve the IV values of my pokemon and change to Dream world abilities for a few of them (only realeased ones i tell you), whilst still being basically legit (legitimate?)

What is PID, does changing it make my pokemon ilegal if they are registered to my OT, or Secret ID whatever that is?

Will my pokemon retain my secret ID or whatnot when i send it back?

I read that you can change iv without needing to do any other modification is that correct?

Will an edited pokemon still look as if it originated in the game (basically is data the same except for the changed iv, ability) and will it fool all nintendos hack checks (in a could you tell that it's been edited kind of way)?

PS. about that last one I'm not going to use them to cheat in nintendo tournaments or stuff just play wi-fi/irl battles with friends and in the local gaming den i just want to have the cake (legitimate/legit pkmn) and eat it to (good iv's abilites)

PSS. also I don't want to get banned from gts/dream world and so on (don't want to miss out on the event-pkmn)