If it's just one layer generally most roofs can take another layer and the weight is fine.

People would be better off understanding basic economics than watching this podcast...the concepts of supply and demand curves, substitute goods, dead weight loss, producer surplus, etc. are far better indicators than "it might happen in 7 years it might happen in 18 years". 

If you are wanting the crispness that white can bring, stick to lighter colored tones.

I would give more weight to out-of-town customers who are less likely to move PMs.

In my case I have very old weighted wooden windows, the contractor I talked to said they are the easiest to replace. 

And the entire weight of this issue does not fall on you.

Start when you don't have the weight of other obligations.  

You may not have seen much work done, but experience and knowledge is worth it's weight in gold.

It's also hard to know if contractors are being honest or fluffing the numbers etc...If the rehab number came from a reliable source then it carries more weight, but if it's just a guess by a wholesaler or someone with no experience it's probably going to be too low.Bad wholesalers are notorious for lowballing rehab numbers and over estimating ARV...

but  I strongly believe - a good real estate agent is worth his weight in gold .