I am not in the same situation but I would assume they would either charge your state tax or not charge tax. Hopefully some other buyers on here in the same situation can chime in on this exact situation.
In my state, Colorado, Tesla only charges the state tax. Then we have to pay county and city sales taxes when registering the car.
Yes. Anyone who takes delivery in Fremont has to pay California taxes. There are lots of discussions about buyers taking deliver in Nevada, Oregon, etc. instead of California. It would be better in your case to just take delivery in Oregon.