How to handle a PI who constantly threatens to kick me out of their lab?
Don't walk, run.

This kind of behaviour should be viewed as entirely unprofessional and unacceptable in any working environment; it astonishes me what gets politely overlooked in the academic world. What you describe is bullying. While the work may be exciting, it is doubtful that you will ever be able to flourish as an independent researcher facing daily abuse from your supervisor and suffering the toxic secondhand effect of your supervisor abusing your colleagues. I cannot imagine that after several years of that you will still be able to maintain the same level of enthusiasm for your work, and perhaps for academia altogether.