Regarding this deal in particular, it sounds like the exit strategies are limited, which is a huge red flag.

You've sought out an agent to work off market deals for you (ethical red flag and possibly not legal for an agent to do according to NAR), then they BROUGHT YOU A GREAT DEAL, and now you're concerned that they might have a motive other than your benefit?

Also, on a complete side note, is it a red flag if a property in the north-east doesn't have a heating system for a period of time in the winter? 

The older gentleman is a doctor and his credit and background check come back great no red flags there.

100% agree with @John Warren make sure you aren't in a war zone and those prices for a newer built building are a red flag.

(That smiling picture of you with that pulsating bruised red nipple will get the attention so don't worry.)

Crews might be rolling out a red carpet in front of the Dolby Theatre while crowds of people snap photos from the top deck of a passing tour bus.

When you talked to them, were there any red flags?

The property in question is outlined in red. 62P4

If your investment capital is the root and trunk of the tree, the leaves are the cap rate.