Just trying to understand tax implications. 

Do i have to actively manage a property to use a bonus depreciation tax write off? 

Taxes would be around $500/year for the land only.  

I'm still thinking if this is the right move for me given the high property taxes there, hassles of out-of-state management, additional CA taxes, as opposed to simply investing in index funds (which might have more returns).

There is no tax advantage to doing an LLC.

4 legitimate units as opposed to 2.3.

It was not a 1031 exchange, so we are now calculating our taxes.

For the District of Columbia, is there a template or any advice on what works to challenge property tax assessment increases?

Here;s the key : Postion your investments in real property so that the investments can take advantage of ALL of the following: 1- cash flow 2- equity build up through loan amortization3- price appreciation4- tax benefitsThe LEAST important of the 4 above are tax benefits as investing through a retirement fund, ESPECIALLY ROTH, will provide tax shelter itself.  

Tax benefits.3.