short question:
bwc.
- can you use this as spammable skill usefull? or is only transmuted good and only as a support skill?
- the burn dmg is working as a dot applied on hit or only if monster stand in the fire graphic?
- Yes, within the CD limits. It has various damage types.
- I believe the RR is only while the enemy stands in the BWC, though. Confirmation, anyone?
- The dot follows normal dot rules. It applies a dot/s for the duration + any durantion bonus you have. Further, while the enemy stands in the BWC, it can reapply (not stack) each second. This is why it is sometimes used as a devotion proc.
yes it works 
I tried to play it with a Commando, The Damage is good.