I am considering selling a single-family rental in DC and/or looking for a new commercial loan to purchase the building as much as I (or we if my brother decides t partner with me) can to be a majority owner.

It's a strong cash flow market.

A 1031 exchange is a great option, but only under certain conditions if you end up making money.If the property is performing poorly, it makes sense to sell and put your funds elsewhere, unless you have a buy and hold strategy and you are okay with riding things out for a bit.Single family home rentals aren't what they used to be in terms of profitability.

I'll cut and paste what we send out for the initial approval for a loan on multi-family, but it's similar to what we ask for for a MH Park.

I am looking at a property here in FL that is listed as a single family for 470k but is functionally a triplex (3/2 house with a guest house in back that has 2 units, one is a 1/1 and the other is a studio, both units in guesthouse have kitchens).

Usually the programs are only available on one unit properties such as single family residences, condos, planned unit development (PUD) and townhouses. 

I'm a first time landlord (family is all landlords but in other states) and also not looking to shell out 1 months rent just for a lease.

This market has low equity appreciation, a dearth of multi-family homes, but a stable renter's market.

Im selling some single families and if I can work things right will hopefully buy a small 12 unit deal due to getting a # from an owner 2 years ago - I talked to him yesterday and he shot me a price -seems fair - he told me he's 80 and has others - I'll be meeting with him in a month or two for coffee and see what happens. 

I am investing in REI for my families future and have absolutely no intent of looking to "get rich quick", replace a job, or use father time as an excuse to make hasty decisions and potentially leveraging myself too far.