Yes. go to the pastoria gym and one trainer should have it.
Ace Trainer Shannon on route 221 has a Lopunny, inside the grass to the east
Eevee (Day or Night), Chansey, Golbat, Togepi, Pichu, Cleffa, Igglybuff, Azurill, Budew, Buneary, Chingling, Munchlax, Riolu, Woobat and Swadloon.
Yes, because whoever owns the egg when it hatches is considered the original trainer.
Azurill
You can get azurill in pokemon diamond and pearl by either breeding azumarill (or marill) or capturing it in the safari zone. :]
Cynthia
Cynthia
beat every trainer
none they are wild on route 214
Azurill evolves into Marill at level 12 in Pokemon Indigo/UnovaRPG.
yes, on the snowy route
a skier in snowpoint mountain has one
hippotas is on iron island
Ace Trainer Shannon on route 221 has a Lopunny, inside the grass to the east
Gardevoir isn't in Platinum as far as I know.
None of the trainers have a azurill but breed a azumarill and another azumarill opposite genders in the daycare and make sure one is holding sea incense.
one of the trainers in the lost tower near solcion town has a cleffa.