I'm not aware of any guidelines or anything in the standard deed of trust that deals with that scenario, so I really have no idea. 

Who knows, it might have been that she the agent did not like the way things were progressing and she may have sabotage the sale.In every case I have used my strategy (no buyers agent), I worked through the selling agent which worked to my advantage as I now have the sellers trusted agent working on my behalf.  

Hey BP,I’m managing 4 units for a distance and am trying figure out the best system or solution to the keys.My first thought is to have a boots on the ground person I can trust to collect keys and take pics of units when tenant leaves.

As you earn their trust/respect, they'll open up to working with you.Keep the BP community posted on your progress!

I have heard that it is hard to get accurate lien info nationwide and to be careful when trusting data from providers claiming accurate tax lien and divorce data nation wide?

California is a lien theory state... so based upon that, a mortgage or deed of trust executed by one joint tenant would not sever the tenancy unless the property was sold at foreclosure prior to the death of the party who incurred the lien.If the other owners executed the HELOC they would be pledging their own interests as collateral... which I doubt is the intention.

Should I trust it and hold the property for a while or sell and make a quick profit?

The use of trusts becomes particularly compelling considering the ever changing relationship dynamic.A loan from the parents to the children's venture might make a lot of sense.As a general rule however, I don't recommend lending money to family or renting to family (or close friends). 

A combination of trusts and LLCs etc do both.

In the past few months I have moved to Equity Trust for my HSA and SD Roth-IRA and it has been pretty smooth so far.