I have noticed you have to have regular arrows in your inventory to fire tinker's construct arrow from the tinker's bow, idk why.
Updating mount and blade seems to fix some bugs involving dual wield but I think Technic won't help support mod packs with added mods.
Finally I can also confirm the no non-vanilla loot issue let me know if anyone has a fix cause if I kill another 500 hp super named lobber with wither to receive sub-par loot I think I will cry. However maybe we were just spoiled by 1.0.