The language for the loan approval in the contract basically just says the buyer has to make a good faith effort to obtain the loan commitment within 45 days of the contract or 5 days before losing, whichever is earlier.

The floor area for an accessory dwelling unit shall not exceed 30 percent of the residential floor area of the primary dwelling or 600 square feet, whichever is less, and minimum area of 150 square feet, or as specified in Section 17958.1 of the California Health and Safety Code.6.

Likely they will only lend 80% of the appraised or purchase price, whichever is less.

Why not both take their referral and find your own and compare them and pick whichever is better, some agents have hidden gems others well.... don't3.

Just secure their loan via a deed of trust or mortgage (whichever security instrument is used in your state) to the property being loaned on.

Google him for his website, then go buy whichever incredibly underpriced course of his that has his Lease Agreement.

If you took the pics on a cell phone you might want to invest in a clip on fish eye lens to get more of the room in each shot. 

FHA will treat them the most strict as they treat all student loans regardless of your payment as the greater of 1% of your balance or the full payment whichever is higher unless the lender can document the fully amortizing payment is less than 1%. 

On BiggerPockets you can connect with a few agents in whichever state (Florida or Texas) you end up moving to, and specifically your sub market.

I found a fourplex in my area, looked up the owner, and finally got his cell phone number.