They stated that the paths shouldn't be required for a certain class. E.g A warrior shouldn't be required to take the explorer path for example. Having said that, it was also stated the paths should make some encounters easier. So read into that as you will. I'll say this much though, if one path has a damage reduction or a massive heal or something that increases damage by a flat amount etc etc, then guess what, yea they will affect endgame everything.