For the first part: you should use Asc bolts. Your Chaotic Xbow can still use the bolts, but it will only inflict as much damage as royal bolts.
For the second part: last time I tried it, Dragonbane is very good at QBD (it basically makes you hit QBD all the time), however your off hand should ideally be either Attuned Crystal Chakram or Death Lotus Darts if you have access to either if you use abilities. Otherwise Chaotic is good for off hand if you go legacy
6,924th to 30 hunting, 13,394th to 30 summoning, 52,993rd to 30 Divination
Kiln Record (Post-EoC): W 25 - L 0, 14 Uncut Onyx, 8 Jad hits received (Best record: Two in the same kiln)
Obby set renewed post update #2: 0
QBD drops: 21 crossbow parts, 3 Visages, 1 Kites, 2 Kits
Max Port Score  Achieved: 27th April 2013 (World 2nd)
Farmyard Rampage ranking: 12th, 50,000 Kills.
Dragon Pickaxe Drops: 1 (Times after I first entered Battlefield: 2h)