Would it be best to use the bank I have now for the primary mortgage?

If it is a recent mortgage, then it may make more sense to do a cash-out refinance.

Most Californians will just use living revocable trusts for holding assets to avoid probate and allow for proper estate planning, and then achieve liability protection through other means such as LLCs, insurance, etc. 

I was recently laid off from my job and have three issues: 1) No way to get a conventional mortgage 2) Need a place to live, and an advantage: sizeable savings on stock, bonds.I want to start investing in RE (ideally multifamilys), but for now I want to start small: buy a condo to live in, and [whenever I buy a multifamily I could move to] rent it.I would like to evaluate my high-level strategy, and get your comments:* [Soon] Get a "securities line of credit" worth around 15% of my savings.

I doubt any algorithm can properly price your property every month of the year. 

@Michael Campbell if there is a mortgage on the property it should have been recorded at the local Clerk's office.

I was listening for the part that worries me: liability, but he acted like it wasn't an issue with a signed liability waiver and proper insurance.

These questions were helpful for me to think through when scaling in this business.Aside from that, it is essential to learn how to properly underwrite a syndicated deal..much different that a straight up acquisition.

I used most of the money to supplement my mortgage and some renovations on my portion of the house also, but the past year I have been saving most of the profits.

You want to invest just to have a place to live and potentially offsetting your mortgage payment by renting out the vacated rooms or having x amount of cashflow in the future?