I did not know of this time log requirement for STRs, so as a newbie I am going back through emails, texts, phone logs, invoices, etc. to determine how much time I spent on everything.  

Freddie has a reno loan product that can be used for investment properties; this is only for first position, though.For the Heloc - it goes back to whether your mom wants to continue carrying the loan for income, and if so, how will you pay off the heloc once the rehab is complete?

My plan is to funnel the rental incomes from all three properties, along with my W2 income, back into the HELOC while covering all expenses from it as well.

Then there you go.One thing I am looking to try to do but haven't done yet is buy something with zero down on seller finance, put the rehab on a 0% credit card, then refi the seller off in 12 months and pay back the card. 

Federally backed loans have very severe penalties. 

We have life time losses to uncollectable rent/financing payments to prove we back up this claim.   

If you are going to use a HELOC you need to do a strategy that pays it back full(Flip, BRRR).

@Michael Almand, for a full line-by-line breakdown and scope of work, my preferred contractor will charge about $250 to walk the property but will credit it back if he and his team are given the job.

.: Is it legal, per the IRS, to rent my primary home back to myself? 

It is a one two family and a single in back.