Two Weapon Fighting and Rapid Shot.

[notjer]

I believe you still need two hands to use a repeating crossbow more than once per round.

Oh crap XD

Well then we need to metagame -> wizard with craft (weapon) and the spell fabricate + new kind of enchantment (pull back the string), it doesnt states any strenght requirement to reload the crossbow which makes the unseen servant a brilliant reload servant -> Self-reloading repeating crossbow! -> munchkin problem solved!