Again, that's a quick analysis on what you're mentioning here, but it sounds more like speculation than evaluation.  

If you are very handy and have generous amounts of time to put in, a few flips can be a good way to get immersed in the process of evaluating structures, offers and negotiations, contract to close, and rehab. 

Ask them to evaluate the boiler system at the project property.

I suppose it's still up to the investor to set the criteria (e.g. condo with x price point, HOA, etc) and have the realtor setup searches that gives the investor a list to evaluate.

For items like an old roof, I would personally recommend asking for a credit/concession as you can get that taken care of relatively easily post-closing.

This means YOU need to learn how to evaluate a rental application!

Also as you like at multiple states it may require evaluating multiple property management groups.

As I have been looking at properties and listening to some podcasts, a principle that emerge is that if there are separate meters, then you can easily charge the tenants.

Whenever issues or problems arise, I can easily pay the best professionals to fix the problems.

Where you able to get out of them pretty easily?