Ok, so I re-read the entire thread here. You say you had the carbs apart and cleaned them well 3 times. But you never indicate what size jets, or needle positions. You posted earlier that the plugs were badly fouled, but haven't yet shown plugs since cleaning them up.
Even if the jets are stamped with the correct numbers, its possible the PO drilled them out, or re-jetted using non-stock brand/sizes. Given the torment that bike has seen in its life, I would have the carbs FULLY disassembled and cleaned. Since it used to require Starter Fluid to run, that tells me they are wicked clogged up. Now the bike won't idle below 2k, so there's a strong indication of improper fuel metering.
Can you provide the carb stamping number (right side of #4) so all adjustment advice is relevant to your carbs.