At this point, instead of continuing to pay the interest loan payments on properties that we will never be able to financially finish since the rehab loans will not cover the actual cost of the rehab, I wanted to know the ramifications of returning the properties to the loan servicer, deed in lieu.

I don't think the sellers agent does much. maybe take pictures and "review" the contract... the buyers agent is the one that shows the property and the one that draft the contract.

Take the toilet out without damaging it, put a sanitary cover over waste hole, put toilet on shower floor.

Bad news you may also have to cover your own commissions. 

I do not know much about San Antonio market so will cover pros/cons of San DiegoCons- price of entry.  

My business partner provided the upfront cash for the down payment, and we used hard money to cover the remainder and the rehab costs.

New pictures, updated amenities etc can help raise your rankings.

With the situation you're going through, your first thought was likely "I'll raise the rents to cover this." 

My bookkeeping firm provides me with a steady active income, which allows me to keep doing deals, cover unexpected expenses, and navigate the occasional black swan event.

The part of the home you live in can be covered under an HO3 (homeowner’s) policy, but the rented unit needs to be covered by a landlord or dwelling policy like a DP1 or DP2.