If you go your parent's route and you get a good W2 job, obtaining loans will be much easier. 

Brought 1st Rental property for $25,000 — Obtained financing based on a subject-to appraisal that came in at $50,000 @ 80% LTV = $40,000.My original thoughts were I would be able to only put $15K into the property and technIcally have none of my own money in the deal.

The transfer of the asset, with the sub-to note and pending tenant option deposit will also be somewhat complex and perhaps difficult under a custodian managed self-directed IRA.  

If you're even somewhat active in the purchasing/selling space, I highly recommend you obtain your Real Estate license for the following reasons:- CE credit often overlaps and counts toward both licenses.

Hello,I want to obtain my real estate license.

Especially if you go through and asset based lender.

I would like to obtain a LOC to brrrr properties. 

We are under contract for 152 units poised for a light reposition of the asset in Yuma, Az.  90% occupancy going in.  

should i obtain a CPA and a lawyer before purchasing my first deal?

Solo 401k plans have penalties for PTs starting at 15% of the violating transaction.With either structure, it's generally recommended that you do not commingle retirement and non-retirement assets.