I've had two quests (collect bounty from...) for each in my inventory since as long as I can remember, and I can't hand in the quests to either - does anyone know of any console command that can remove the quests from my active journal (without, I hope- doing damage to my save game?) Thanks for your time and help in advance!

Install the Unofficial Skyrim Patch?

Its that 'Return to Skald/Brina' right?

According to the uesp, console commands will not clear the quest unfortunately.