Kawdude,
With regards to the carburetor, the needle doesn't have anything to do with the lower rews but it does affects lower-mid / mid-high (you might call that middle rews?).
I had the very same symptoms as you did until I changed the carburetor. Tried it all, tweaked the timing searched for leaks etc. but fact remains, the engine does not ignite unless it's got air/fuel...
Changing the idle jets to really small ones will also work. No fuel - no kick-backs...
If you dismount the carburetor and check the throttle-play when the throttle is mounted you will probably find it is not a perfect fit... That?s causing your problem. It sure caused mine.
I do agree, it's very frustrating when the bike almost throws you off the road just because you do not rew it.
//John