So I have a '88 RX7 GXL with a very sloppy shifter. It shifts into gears fine, when I can find the right spot to get it into gear, but when in gear the shifter will wobble and move in all directions for all gears.

Is this a shifter bushing issue?

 

Yep..bushings.
here:Transmission

 

Why thank you sir!

 

also if ur shifter wont reclin back to the center and just hangs leaning towards the 1st and 2nd gear. u might have to chamge the shifter spring. easy fix if u habe the knowledge

 

Shifter bushings are a common problem with RX7's due to the age of those cars. The bushings are plastic and with heat and time they tend to wear/break. You can find them on ebay or any mazda shop. They are relatively cheap. Good luck!