Multiple Issues on Mac OS

We are using iMac's and experiencing a lot of problems, I'd say 20-25 out of 30 pupils every session experience at least one of these issues.

Code builder fails to load. We have found leaving the world and joining again fixes it for a while but the application crashes most of the time when doing this and the issue can happen again.
Sometimes the green play/run button is behind the text at the top of the coding window meaning we have to reset the code builder.
The fullscreen glitch is still there after a year, we have to play in windowed mode.
Characters get stuck auto-running, the only way to fix this is by double tapping the direction button that they're moving.
Random game crashes.
When hosting a shared world for a class, we have frequent disconnects.
As I write this one student is stuck in python mode, despite relaunching the game multiple times.

There are probably more issues that I have forgotten but it is barely usable in its current state.