Can i repeat one favour? (For +6 X item?)
Or maybe once for all?
And what do i do to get most out this then?
Do smith works with lvl? Depest lvl? Bosses? Is it even good (of course in efficency)
Was Reforge overhauled? Or still gives +1?
It depends a lot on what items you have. Generally upgrade/reforge/harden are better if you already have good gear, and smith is good if you need to fish for a good weapon or armor. Reforge, harden, and upgrade can each be used a second time, but the second use costs 1000 more favor.