I plan to purchase a 2-unit+ property as a first-time owner to get all the advantages Maryland offers, and scale from there. 

Together @Amelia McGee and I  self-manage 60+ units and have a wealth of experience in landlording.

.—(1) When any lands are sold for the nonpayment of taxes, or any tax certificate is issued thereon by a governmental unit or agency or pursuant to any tax lien foreclosure proceeding, the title to the lands shall continue to be subject to any easement:(a) For conservation purposes as provided in s. 704.06 or for telephone, telegraph, pipeline, power transmission, or other public service purpose.

It doesn't necessarily have to be IN the unit, but it does need to be onsite.

Because it is outside of the United States, it is difficult for us to locate it.

any good recommendation for good property management company in South West San Antonio for managing upto 20 units multifamily

I intend to add a closet to the den and make it a 3 bedroom adding value as well as remodel the entire unit.

Why can't you MTR 1 or more units of the 4 plex?

We have a large property management company our entire office uses it to manage hundreds of units.

It's a good idea to work with a CPA who understands self Directed Retirement accounts and I definitely recommend you check with a CPA before you do a Roth Conversion so you know the tax implications.