Riddick will show up later, when your character is at a level that you can recruit him. For me it took awhile to get Riddick and by the time I could, I didn't want him.
As for getting through Near Dark, you can shoot your way out, even at a fairly early level. If you decide on this option, hopefully you have enough people with pump and double barrel shotguns. Form a phalanx and let the deathclaws get close. You don't need t see the deathclaws to hit them, just fire in the right direction. Save the double barrels for the ones that get close and the pumps to thin them out after the doubles do their thing. Save a few points for hasty retreats of wounded party members. Ideally the deathclaws will hit your group in ones and twos, maybe even threes and only from 1 or 2 directions. Keep the group tight to minimize damage to particular players.
This can be a lot of fun.
Don't do this in CTB