>>20067541>>20067663I think this is pretty good guide to genning Gen V pokemon, in case you haven't found and read it through yet.
http://projectpokemon.org/forums/showthread.php?14026-Guide-How-to-generate-Gen-V-Pok%E9mon-in-Pok%E9GenAs for Gen V event mons, I genned those two today and both passed. Since IVs and nature are not related to PID in gen V, I'd say it's safe go nuts with pokegen, even when genning event mons, and bestow your creations with whatever IVs and nature you want.