The only issue is a $35K membership fee.

E&O insurance is typically provided to you by your broker, usually a fee per closed transaction, $50 or so.

If you would rather stick with your seller then you can farm out your buyer to another agent and take a referral fee, but that is still pushing the line.

Well now I have a little bit of savings after working hard and saving like crazy for a LONG time and I've decided to buy a home cash in Memphis so that I have less risk (vacancies, HOA fees, mortgage payments, etc. all scare me, being a newbie, so I see this as the lowest risk way to get started because even if the home sits vacant for a year I would only have to pay taxes and insurance). 

I'd also be renting to him at market rate and cash-flowing (until he decides to buy), and I'm going to collect an option fee from him.

You should have joined all 3 simultaneously when you went to the local board in person.Membership should be immediate after you pay all the yearly dues and fees and you will start receiving materials from the National and State boards in the next few days and weeks.

Now deduct 10% for management fees (even if you manage yourself) and 10% for repairs and improvements each year (since you are rehabbing up front this may be more than you need but better to be safe).

Also, for your first deal, your fees would be very reduced since you are learning on their dime.

Who has the least expensive set-up and maintenance fees today?

Save half the commission when you sell by using Realmart or a similar online MLS listing service, for a flat fee of a few hundred dollars they put you on the MLS and then realtors will bring buyers to you without you having to pay a listing agent of your own.