Danielle,
I would be cautious with fix and flip projects with the current uncertainty in the market. Your questions all comes down to the numbers and the market area you are in. The reason I say to be cautious is because most projects take 3-6 months and a lot of over head at first, this can be a little risky at a time like this. As far knowing when something is worth the flip you would need to take in account the project costs, profit, ROI, MAO, and the 70% rule. I think the location of the flip is key, it will determine if it is "worth" actually fixing foundation issues, mold, and termite damages. However, I would make sure you have some really good contractors in place.
For you first questions, I work with buy and hold investors, and I do see a surge of demand increasing the EaDO area. Again, there is still a lot of work to be done. Maybe look into the East River end projects that are taking place.
If you have any other questions please feel free to reach out.