Loose_Cylic, I would most definitely do the full ATPL exams if I were you. People I know have done the CPL, only to wish they had done the few extra exams. There are lots of employment opportunities in the North Sea at the moment especially with your experience. Plus the $$$$$$ is a lot better offshore than Police / Hems.
I've flown in the LA basin and know what you mean about BUSY airspace, don’t get much worse than that
If your gonna take the plunge, I think now is a good time to do it