Sub 2 GG man!

du dum

Yes you can use DLC items in FC4 Runs. I used Driller for the most part of my segmented run.

Yeah forget that last part lol

No you should always have a video of your run so the mods can verify that you didn't cheat. Especially if you are doing Any% Non-Alternative Ending or 100% But you can ask Chickenboh if he is willing to make an exception.