The IRA is treated the same way as your current IRA for tax purposes, but you will have the ability to invest in assets such as real estate that are not handled by the mainstream brokerages.There are two types of self-directed IRA plans, and a lot of good info here on BP on the topic.IRA Custodians hold accounts and do the processing, but just have a different business model that supports documenting the IRA's investments into things like real property, notes, etc.  

Right now I have multiple part-time jobs, but none with a stable 2-year background history.

Try Pacer.gov its a court document site, I use it for locating recent chapter 7 and 13 discharges.  

I searched high and low about the tactical steps involved in doing a “subject to” deal and it took a while to learn and document the steps.

Looks like history does not repeat but definitely rhymes.

A written document that's signed between both of us stating we have a 50/50 share in the property?

Of course, it all depends on the quality of the partner(s) you choose to invest with.Within the IRA realm, there are two business models.IRA Custodians (generally trust companies) can hold an account and document that account's investment into non-traditional assets.  

@Chris Ahlemann If you can document the condition of the unit, your contacts with the landlord and their unlawful early entrance of the apartment then I would pursue filing a small claim.

I once insisted on reading the 25 pages of documents that accompanied a no interest lead renovation loan.

You're not looking for a recent history of properties that have been purchased in cash - you want to know how many people in that area have obtained a mortgage and planned on living in the property as their primary residence.