For instance, not long ago I bought a 9 unit apt with two retail on first floor for $200k and at purchase the rents were $6400/mo.

In some instances lenders may allow exceptions a bit above that with compensating factors. 

For instance, the Poconos have remained a popular option because of its year-round tourism draw, with skiing and lodging in the winter, hiking in the fall, and camping around lakes in the summer.As others have said, going into markets with one draw is risky.

I'll show you one quick example that proves that PUP is better than LLC in a standard case.Take for instance you have a 500K property completely paid off. 

And also not a dig on Brokers  but Brokers can basically offer zero help in most instances if your having issues.. they get paid to close the loan then are out of the picture they have no authority to do workouts or modify terms etc U would be working with the actual lender then.. 

One example in Oregon for instance if your going to buy 1 home and fix it up to sell to the public you MUST have a developers license or a GC license.   

For instance, selling a $50,000 house and making $1,500 is not a very attractive proposition for an agent, but selling a 1 million house and making 30,000 seems kind of unreasonable as well.

If not, in many instances it does not end well: while hope everything goes good forever - always good to have a what if plan just in case

For instance, do you say that they shouldn’t nail anything to the wall and only use command strips?

there is no typical.. but in this instance going forward I would meet them and you hand them your check and they hand you the sign Lien Waiver/release.