You'll most likely still need a coborrower at first, but may be able to refi them out of the deal in a year or two once you have qualifying experience and operating history - then you can likely use all of the rental income towards your gross income. 

In efforts to get more experience with IOS, we are seeking a financial partner that potentially has experience with this asset class. 

You get PM experience, lower expenses, you don't live with your parents anymore, etc.. 

But if you only have one rental and you get a bad tenant you are sunk.Read the laws and talk to some mom/pop landlords with decades of experience.

Purchase and rehab properties will have a similar reduction, but as long as you have experience within the US, you should still be able to get some pretty good terms.

I'm interested in the VB/VA and OK City markets (lots of family in OK now), but then again, I don't have much experience analyzing markets. 

There are people here with WAY more experience than me.

There's a lot of other things to consider here but I'll go through your list and make some suggestions based on 10 years of investing across various asset classes - single family, multifamily, industrial, storage, retail, office, etc. and I've had experience with section 8 housing, BRRRR, flips, etc.Purchasing rental properties?

I've closed a bunch of loans with Kiavi, Roc, and a few with ABL, I also closed with RCN, Easy Street, Lima One, and some smaller private lenders.I've come to the conclusion that the experience at the lender is not globally good or globally bad. 

They are going to finance you based on your loan to value, experience, and liquidity.