Being in the industry for over ten years and running over 500 machines myself I can only say they are bad dudes. 

Not to mention, they probably won't want to admit it if a building they manage is in really bad condition.If you're serious about buying you should first talk to fellow investors and define your buy box.

Our logical process:1) Use Neighborhood rankings to narrow down area of city you want to invest in2) Focus on getting to know that Neighborhood(s), so you know the good & bad streets, block-by-block.3) Be patient to acquire properties on good streets that meet your buying criteria.Our rankings are done with a "bell curve" approach.

Such a bad first impression if the buyer is standing there while the realtor is struggling to open the door.

Probably even more from the bad deals..Long term you are better off with better real estate.

It may not be a bad idea to also be added to a MLS search to receive any new build listings. 

That doesn't't sound like a bad idea.

Brandon Turner's Rental Property Investing book is an excellent primer to understanding the happy path for purchasing a property - however in this market it really comes down to having bulletproof assumptions on rents/taxes/R&M/etc. as with rates as high as they are/inventory as low as it is, there is less cushion in your returns if you analyze properties with bad assumptions.

It's usually a very bad idea to go into business with friends or family. 

I've read a lot of bad information on how some gurus are promoting techniques that are flawed at best, fraud at worst.