I know my FL permit is no good there, but I still like to ahve one w/ me.  Is it a crime to bring in an "unregistered" handgun or something, or would i have to have a firearms owner's ID card or something like that?

Can I have it in my glovebox?

I recall threaded muzzle on pistol are prohibited.  Is there a 10 rd mag limit?

San Jose Area, S of San Fran I mean.

Read the stickies at the top.  But short answer yes.

No magazines over 10 rounds.

No threaded barrels.

Safety "Ban" list does now apply to personal weapons.

You're not going to be able to carry it legally outside your "residence" .  Transporting it means in a "locked container unloaded"  Ammo can be in the container, and in magazines, not physically in the gun.

Can't have it in the glovebox, center console, must be in the trunk or if no trunk out of reach of driver.

No id card, etc.  

As long as you stay out of East San Jose and a few other rough areas, common sense is all you need.  TV and movies not withstanding, CA is not a continuous gun battle all over.