I assume keeping the front door closed and locked at all times is common sense and doesn’t require to be spelled out.

We have a small management company and our common practice is to inspect the units every three months or so.

This is extremely common in areas of C D quality properties.. not necessarily the tenant that did it could be just your typical theft when a home goes vacant. this is why its critical to have a vacant home policy in force on your rentals..

Is that common? 

If you use the search function, there are a number of threads on this.Pros-you can rent by the room and make more moneyCons-students are often less experienced at living on their own and may do things that result in repairs (eg wrong soap in dishwasher), higher turnover, more calls to deal with things, higher chance of parties.If you do it, you may want to get a cleaner in once a week to clean common areas (students clean their own rooms and keep the place tidy, wash their own dishes) and you will need to get someone in to take care of the yard.

I would say there should be a few options at that loan amount - the most common minimum for DSCR lenders right now probably more like $100k or $125k - I would say only a small portion have as high a min. as $150,000

That's also an option to temporarily bridge the gap of quitting a full-time job.It's also important to be making enough on your properties so you're cash flowing enough so you can buy more property - sounds like common sense but as mentioned you can always freelance or do something you enjoy part-time to bridge the gap in pay.

Unfortunately , this seems to be a common bait and switch scam .

That's a common thing that appeals to out of state investors I think.. 

There are plenty of NNN tenant-in-common investment providers out there, along with DST sponsors, deal syndicators, etc.