http://projectpokemon.org/forums/showthread.php?26272-Complete-Black-2-Save-Data-(DOWNLOAD)
I'm not sure if it has ALL the Pokémon, but it's worth a shot.
Try using File -> Export/Import Backup Memory instead of editing the dsv.
I know there shouldn't be any difference, but doing that fixed some mystery issues I've had in the past.
Legality checking is largely objective, but some things that are possible are unlikely. That warning is a subjective observation that it doesn't normally happen. It is common in hacks, but is not proof.
I think getting badges triggers other gameplay events, so messing with flags like those is a bad idea.
Depends on the event. The elite four in the 4th gen doesn't actually check for the badges even though the NPC says he does. An advantage to badge editing is that all Pokémon are usable at any level.
Hit. Well, watched. I lost interest with Bleach because filler. (I'm sure I watched other things on it, I just don't remember.)
The next person likes sniping.