And, regarding your last couple of questions...
No, you won’t get inspected between smog tests. So you can run “illegal” aftermarket parts in between inspections, but when the DMV sends you your registration renewal and requests, no DEMANDS you get a smog inspection certificate to accompany your registration renewal, you better put all the stock and/or smog legal goodies back on and do so neatly because that’s part of the visual inspection too! Can’t look tampered with. Granted, the CA DMV doesn’t require a smog certificate every year, but when they do, be prepared to reinstall the legal stuff for the test. Then, you can get the certificate, mail it in, go home and reinstall all the not so legal stuff!!
P.S.- where in Cali are you? I’m in SoCal/Ventura County