I'm not sure how California law works but in my state of Oklahoma the first step is to get a judgement against the tenant in small claims court.

In cases of court evictions, collections or judgements, are copies of their gov't IDs, address, birthdays, enough? 

Sometimes they will get a guy like this who does a couple jobs well and then does something like this, but the reality is they are basically judgement proof just like super low income tenants.

In a state that a lender can get a deficiancy judgement if the deal goes through foreclosure the client can get their credit trashed and end up with a big fat judgement against them.. ( state specific).the reason your probably getting buyers that want to do this is because of all the online notoriety currently like Pace Morby who is huge in the space and the legions of students and followers and then to a lesser extent there is BP's own Sub to Guys..

If it goes beyond that, you could take them to court and file a judgement, but most times, you'll never see that money.

We'll then write a promissory note for the amount, maybe attached by mortgage (if not, a lawyer said attaching a judgement lien upon default isn't too hard, provided no chapter 7 bankruptcy filing).Has anyone done this post closing?

To be honest this may be a judgement call since something the size of a toothpaste cap should not stop a sink from draining. 

Speaking of fog, John has very good advice about the noise, which may fog your judgement!

Penalties, outstanding mortgage balances, liens, judgements, etc... paid in full.

In cases of court evictions, collections or judgements, are copies of their gov't IDs, address, birthdays, enough?