With regards to CA:
Med school: Ridiculously hard to get accepted in state--don't count on it. Maybe 25% odds (my best guess from how things were when I applied). Certainly not 50/50.
Residency: Easier to match in state if you went to med school there simply because you'll have more local connections/may have rotated at a community hospital with a residency program/residency programs may be familiar with your letter writers/mentors/etc, so you get a leg up. This can be abated by doing audition rotations where you're interested in going. In general, this advice is all true of matching into any state other than where you went to med school, but CA residency programs are typically more competitive on average because it's a more desirable state to live in.
Attending-hood: Have a medical degree (doesn't matter where)? Check. Board certified/eligible? Check. Heart beat? Check. Hire applicant. (True of all states--other than academic jobs and some jobs in very congested metro areas, you'll often have little to no competition.
I grew up in CA, went out of state for med school. For PM&R we only had 5 CA programs and most aren't really that great for what I wanted to do, so I ended up staying in the Midwest for residency. But I think if I wanted to prioritize coming back to CA and ranked those programs higher, I likely could have. Regardless, getting an attending job here was no issue whatsoever. Literally all community hospitals care about is are you legally able to practice medicine. Ideally you don't have a lot of baggage (personality issues, multiple malpractice cases, etc.), but you'd be surprised at how often those are not an impediment to getting a job--once you're at attending the market is very much in your favor.
With regards to matching into states you have no ties to, I found some programs didn't offer me preliminary (TY/pre-lim IM) interviews because they didn't think I was interested in matching there. Now, one of those states was known for not being "desirable" (Iowa), and another was in a not-so desirable city of a mid-tier desirable state, but after my application had been sitting for a while at those 2 or 3 programs I called them and the program coordinators told me I was a competitive/competitive enough applicant, but they didn't initially offer me an interview because they didn't think I was that interested in going there. I told them I was very interested in the program and at least one gave me an interview invite while I was on the phone, and I think the other one or two checked with the PD and gave me an invite later in the day or the next day.
Now, preliminary programs are different than categorical programs. For the later, people are much more likely to be willing to relocate, but if your application has been pending for a while and you know interview invites have been ongoing for a few weeks (follow your specialty thread here on SDN to see as every program sends invites out at a different time), it may not hurt to give a quick/polite call to say "I'm really interested in going here and wanted to check in on the status of my application, verify nothing was missing, etc."