I believe all damage is multiplied with some exceptions (so bane and favor should be multiplied in your example above):
- Darkfire (on-hit property)
- Flame weapon (on-hit property)
- Overwhelm crit (1d6 bonus on crit)
- Sneak damage (1d6, 2d6, etc.)
- any other on-hit things I can't think of...
NWN isn't a straight multiplier though, so I think if you have a x2 crit weapon, it just rolls the damage a second time (instead of multiplying the first roll times the multiplier). For a x3 it will roll it 2x more to get the final number (which explains why for a x2 sometimes you get odd number total damages)
edit: forgot to add sneak