few issues after last drift days, advice needed

[fax0815]

Hi, I´ve had a few problems during and after my recent drift days.
Have a quick read through the symtomes and let me know if you experinced someting similiar in the past? And if you know whats wrong

-the freshly rebuild diff started to make noises and i found axial play on the pinion shaft, will dissasemble to check whats the problem...

-on my way home the steering felt strange, compared to before If you steer quick it will bounce back almost a a sec. later but in the opposite direction!!!
Felt horrible on open road, when passing other cars for example...
Anyone got an idea what´s wrong? Only thing I can think of are worn bushings at the rear, everything else has been replaced/checked.

-I got alternating idle some times, but it goes away if you give it a rev and let it go back to idle. Any ideas???

Thanks