Hello,

I want to play NWN2 with my brother, preferably in a party of just two characters. It seems the vast majority of community made modules for NWN2 are single player, but I wouldn't mind a single player story, if it can be played MP, mechanically.

My question is not, is it good, but is it possible?

What if those characters die?

NPCs don't die in NWN2, they just fall unconscious until the end of battle. NWN was different.

That depends on whether you're playing Storm of Zehir or in the case of mods, whether the mod maker used the Storm of Zehir death system or not. If they did, then party members stay dead until raised from the dead.