I think there are ways to create a moat or put a fence around your clients by creating and using valuable-to-the-end-user proprietary intellectual property.

I have framed up a question specific to my experience, but have also posed a very general question that may be more valuable to answer.

Your earnest money deposit should be held by your title company in escrow until closing or termination of the contract.The buyer has the option/right to select the title company unless it is an attorney state, in which case the buyer's attny would select who will do the title work.That being said, until you know the ropes a bit more, the earlier suggestion about speaking with a competent real estate attorney is valuable advice as per @Nicole Holcomb. 

That is valuable information to screen and make informed decisions without putting any of my own effort into that specific person. 

Looking at what you could possibly get for the price per sq.ft is valuable.

As Scott mentioned, it is vitally important to run your own numbers -- what the seller tells you sometimes qualifies for a Pulitzer Prize in Fiction.I forget how many times BP lets you use the calculator before you have to become a "Pro" member, but even the first time is a valuable education.

They are extremely valuable to you. 

Your hustle is likely more valuable at this stage than your current available capital, especially in an expensive market like So-Cal.

At this point, and in order to have an amicable outcome, I would go with a 50/50 split plus your 20k, and call it a day and a valuable learning experience.

The most valuable part is the rent collection through a portal that updates late fees.