98 Jeep Cherokee 4L 6cyl 4X4 177k Manual

The following problems are a mystery to me:

1) There is a load and constant rattling noise when the clutch is not pushed in, and it is louder in lower gears.

2) When I reverse, there is sometimes a loud and constant clanking noise.

3) When I put it in 4wd, and turn alrmost hard left or right, the wheel pushes back hard against the direction i'm turning, and won't let me go to wheel lock.

4) I refill the AC with the R134a cans every May, as every september, the AC stops blowing cool air. It is fine almost everytime else. Any ideas, why I have solid and constrant pressure for a few months, then nothing?

Any help any of you can provide would be appreciated. TM