Question in regards to the Molten Fury Bow, is it more likely to appear in the group fire raid or the solo fire raid, as I have been try the solo raid for ages now, and I still can't get the bow
The chance should be exactly the same. If you're on an older version, you might have a bug where the bow only drops in the group raids, but that isn't the case anymore in the newest version.
If you got a lot of unneeded raid equipment, you could disassemble them and use the parts to try to craft the bow at the fire raid anvil.