I will however need a design review for a long list of reasons. 

Unfortunately, this is the primary reason I do not use third party vendors for rent payments, and I have posted on here a few times about this (usually when someone posts about a fraudulent clawback), despite the throng of enthusiasm for the continued use of these methods.Each one of my tenants is given a pre-designated bank account (idenitifed in the lease) to which they deposit rent. 

For example, MEP plans are not required for permitting, but if you are designing a complicated house, having a MEP plan certainly helps to guide the trades to know exactly how and where to install the fixtures, versus something they have to figure it out impromptu in the field.

Can anyone suggest a market where one-bedroom STR's that are nicely designed do well?

Security deposits are used for damages and are not designed to be applied to fees or rent. 

Our compromise was to design the upstairs to be like a private in-law suite so it could be rentable on Airbnb when we choose to do so.

Can anyone recommend a design build company that would handle any zoning needs with the city, as well as complete the construction and leave it rent-ready for me? 

After posting I saw in your profile you are a software engineer.....What would be REALLY cool...If you could develop an easy to use Gantt chart software (Think Microsoft Project, but WAY easier to use) that was designed specifically for Real Estate reno / BRRRR. 

Please note the information provided below is a layman's definition designed to provide a basic understanding for the general audience.

We do complete kitchen and bath renovations and re-designs often down to the studs which far exceeds a typical turnover renovation where you'd maybe do minor repairs, paint and lay floor.I think I could probably manage 200+ units using Buildium property management software (or some other full featured app) without breaking a sweat.