While you may have tried a lot of adjustments, have you tried it this way....

1. Richen idle mixture a LOT.
2. Start at 1/4-1/3 throttle.
3. Advance throttle to full.
4. Lean high-speed needle to just rich of peak RPM.
5. Gradually retard throttle and adjust idle needle. Since you know it's rich, you know you have to lean it.
6. Check idle RPM. You may be trying to idle too slowly. Anything 2,500 RPM or lower is fine.
7. Check acceleration. If it bogs wet, lean the idle a hair and open the idle throttle setting a bit. If it just sags dry, richen the idle a bit.

The engine will break in over the first gallon of fuel or so, and handling should improve as it breaks in.