Say a "partner" comes in and it's say the unit is set, rent stabilized with a 3yr term. 

How I would go about it is bring a deal to someone ( a friend or colleague) that I knew had money, offer them the terms I have in mind and continue until I find one.

the terms of your agreement with the agent will lay that out

What were some mishaps along the way in terms of the contract?

in 3 years you can pay off any mortgage 500,000 or less for $1,500 bucks.. or in 5 years a $477,000 mortgage for $100..I am implementing something new for the real estate industry, primarily to mortgage holders & the rent to own industry, as a shorter-term approach to be mortgage free, without cost being an obstacle ..

If you feel confident in the tenants signing those long term leases, this is a slam dunk and you'll have a cash cow on your hands very quickly!

They were abandoned and needed significant work which wasn't a huge issue but in terms of HUD owned properties i heard there can be significant processing periods.

A 4-plex would be ideal and you could play around with doing 1 long-term, 1 mid-term, and 1 short-term, plus you, if it works on your area to upgrade your income.

is RE a great long-term investment? 

Ultimately, you will need to have the borrowed funds in USD and ideally in your US business entity bank account to sail through underwriting with US lenders on US properties.Caveat: the rates will likely be something like 10-12% so it would not make sense on a long-term holding, more like on a down payment on a purchase and rehab value-add project that you will eventually sell (or cash-out refinance) to pay off the borrowed funds in a few months.