Hi Pallmall,
I have talked to CA Board of Pharmacy, and they said; have your preceptor sign your 1500 hours and you will be fine. Since we are foreign graduates and they know that we already done our intern hours in our country.
I have actually done some outpatient also just in case.
No there is no registration of preceptor required in advance. You just have your pharamacist (preceptor) sign your affidavit.
Good luck to you!