Having been there until about 18 months ago, I can add a few bits of info here. Also, keep in mind that Northern California and Southern California Kaisers operate as independent entities, so the payscales and many other things are vastly different. The information I have is for the Northern CA region.
As for your questions:
1) Yes, Kaiser does hire psych assistants, on the condition that you become licensed within 2 years otherwise you lose the position. The salary for psych assistants when I was there was around 80k/year.
2) Starting salary for licensed psychologists (Northern CA) at Kaiser when I was there was around 105k/year, with step increases up to around 145k.
Some of the other points made were correct, others were a bit misguided. You do work hard at Kaiser, but it is always contained within the 40 hr workweek. Most practitioners work 4 10-hr shifts, meaning that you have an extra day free each week to either relax or hold a private practice (many providers in fact do this). PHD12's descriptions of duties certainly mirrors the day to day experiences of some psychologists at Kaiser, but there is also a great range of variability among the clinics. There is absolutely a shift to group therapy in recent years, though many would say this is a good thing. Moreover, with more and more openings in areas such as chronic pain, behavioral medicine, and addiction, there are many opportunities to work as a psychologist within the system in some pretty cool ways.
Bottom line, I am still glad I left to strike it out on my own. But man, there are also days I miss the comprehensive healthcare, no office rent, 6+ weeks off per year paid, not worrying about no shows...lots to like about the system as a psychologist. And between my 4 days at Kaiser and 1 day PP, I was pulling in about 130/yr as an early career psychologist, so I miss that too.