These people are so nice that they are still helping you even though most of your responses are just overglamorizing them or profusely thanking them because they didn't ask you any questions.The other problem is people who tell you how bad they feel for you because other people didn't light a scented candle for your two-line post and spend an hour of their own time trying to help you when you have a new profile, with new photo, and no information.You lucked out with some nice people in here @Scott Meech, but it's because of them that you have information not because you brought anything to the table other than a hand out.

I would say light rehab $30-$40/sqft - Moderate rehab $40-$60/sqft - Heavy rehab - $60-$100/sqft depending on what is needed

You should start with something turnkey or light value-add so you can use the deal to find good contractors.

We want something neither light nor dark—maybe a mid-tone that won’t show too much wear.

Beyond that, a bit more color on this duplex would be helpful....condition?

I see lots of people with unrealistic rose colored proformas that I hope will be saved by an appreciating market. 

First thing I would do is swap out the daylight color bulbs with a warmer tone.

This is a long one, but hopefully I can shed some light here.

Are they picking window style and placement, exterior cladding, color, etc? 

Thank you all for your opinions and insights, in light of the recent information we have banned Bob Prisco from the forums effective immediately for breaking numerous forum rules.