In short, you look at recent sales, the # beds, baths, size of the property, condition, and key features (lot size, attached garage vs no garage, etc.) and adjust the price of the comps up/down to tailor to the subject property.- BPO - Broker's price opinion.

Spreadsheet template:TOP HALF OF PAGE:Addresses of comps - price - date - bed/bath - special feature(s) of house - conditionProperties listed here with dataMedian / Mean / Lowest / Highest chartCommentaryBOTTOM HALF OF PAGE:Left side, improvements since purchase bullet points.Right side, details about how/why you got the property for less than fair market value, again bullet points. 

I do, however, own a 2 SFR buy-and-hold rental portfolio in Birmingham with plans to continue investing down there.

There has been more published, and the laws will continue to develop. 

If they don't complete the contract you resell and continue to generate more income. 

Another idea is putting together a flyer for the HR department to give to employees about relocating and about the features of the new neighborhood the company will be moving to.

He said there is a high chance I'll have to continually clear the lines because tree roots will constantly grow into it, and because the line is made from old clay tile.

My biggest questions are:Should the 12 rentals continue to be kept under a trust?

Then, continue to flip it, but invest your profit (only) in your rentals.Buying rentals is "spending" your money. 

You have to think what would the borrower do, continue paying a house that is $20k+ upside down at higher than rent values or stop paying, let you foreclose, live free for a year+ during the redemption then go rent a place for $600.