Horus Heresy: Conquest Boners

[Homer_S]

OK,

Flaming items, I mean rules questions: 

1) Should Draykavac (pg. 300) be an Independent Character? If not, how does he survive at all with Knights running around?
2) Lords of War (pg.  294): Does this mean the Titans are only available with a Questoris Knight Primary Detachment; not Legions, Lego or Taghmata; or only Titans are available as LOW choices to a Questoris Primary Detachment?
3) Auxilia Infernus (pg. 281): Does the Chem-inferno Gun replace the Inferno Gun or can the vehicle choose?
4) Auxilia Rapier (pg. 261): What is a Lasgun? Should this be an Auxilia Lasrifle?

Note: at least two of the Heavy Support choices are Super-heavy Vehicles.

Homer