most school will ask you for 500h as a flight instructor (insurance requirement)
Absolute nonsense. PPL level instructors all start from ab-initio - the 500 hour requirement is only to be approved for CPL instruction. Aircraft insurance policies almost all state "Any FI", with no hours requirement. That includes up to light twin level (our twins are insured for any pilot with more than 250h TT, ie not people with CPL/IR in minimum hours).
The FI rating and job is immensely satisfying - it hones your own skills to a level where you can demonstrate and teach in most conditions, and to almost all abilities of student. The first few years pay incredibly badly, especially bearing in mind the investment you've made, but for those who enjoy it then it's well worth it. I'm lucky enough to enjoy it!