Any time you can get more cash flowing doors on one lot, they happier you'll be :-) It also seemed like the primary unity was only in need of a quick make ready.

The requirement for the Section 121 exclusion of capital gains on the sale of a primary residence is indeed based on exact dates, not just the calendar year.

If you sell now while its still considered a primary residence you will NOT pay tax on any of that!

If I want to continue to live in my primary residence AND now rent out a portion of it to a renter, am I able to do so? 

The key here is that you do not have a primary housing expense.

Tax free on the gains if your primary residence for 2 out of 5 years.  

Granted, that is still not a guarantee...but the bad PM's usually don't last that long unless most of the properties under management are their own.Another important factor...what is the company's primary focus?

If you are looking for a work space, consider adding a writing desk to the primary bedroom or whichever room has more space.

There's no reason to jack up tax rates just because a house is used as a rental rather than a primary - all it does is inflate the rent at the renter's expense. 

is this for a primary or investment property ?