Without accounting for management fees (I have not yet decided if I will try to self manage), and with planning to raise rents to typical market of $825 for each of the smaller units, and $1200 for the larger unit, does this seem like a worthy first investment? 

One of the biggest factors in successful flips is building a strong team: contractors, agents, lenders, and property managers. 

You may get EXTREMELY lucky and find one for 15% (if they get approval from management), but you will not find one for 5%. 

Between downtime doing Self Storage development, management and Country Subdivisions glad to give input on BP. 

Do you think that is fair - to be forced to pay for your manager's mistake?

we are still assessing the rentals we manage but overall are just finding a few minor issues so far. 

First things first, when assessing property managers, it is crucial to prioritize their ability to collect rent and manage delinquencies.

I am planning to self manage as well and since there aren't many managers in my area I will likely employ a similar strategy once I decide to outsource the management.

It is a lot of work for $200/month to build an ADU then manage it. 

@Kevin Wood: Fixed Asset Management module is included in the QuickBooks Accountant version where you can calculate the depreciation.