IMO you would want to do at least 5 annually to make it worth your while. 

But if you don't have enough to cover expenses, can you fund the expenses from non-IRA accounts?

Hey Cathy,I'll PM you with contact info for my accountant.  

Secondly I maximize my retirement accounts because those can't be taken from me. 

You will need to account for the vacancy (1/12 month 8.33%), repairs (these are short-term items and it sounds like you have already done some of the work yourself - assume 5% of rental rate $130), property management (assume 10% $260), cap x (assume 5% - $130). 

The two boys have never replied to any of my emails but she's been on top of replying and set up the account to pay the monthly rent automatically.

My wife has a 401k account from her previous job, we are in the period to make a decision.

You're earning money as you learn.After you refer (or "broker' or whatever you want to call it) X number of note transactions, after some time you become well-versed enough in the business whereby you can invest in your first note for your own account (using the proceeds you've amassed from your referrals) that you can then comfortably put up some of your own money to build your own note portfolio.If you want some pointers as to how I'd suggest you start, you can PM me.

There is nothing you can put in your spreadsheet to account for that in any reasonably accurate way.There's a reason the locals aren't all over this deal, unless you are unusually lucky.

I suggest: talk to a/your Tax Accountant before deciding.