The ones that aren't "safe" were owned by people who did not maintain them over their life span. 

We bought a 12 unit last year that is under an hour from home-our limit is an hour-it was really well maintained and fully rented with mostly great tenants, and one dud. 

You have a good chance for positive cash flow if your manager maintains the properties well. 

If you are wanting to invest here and live out of town, I recommend interviewing property managers--they are often a one stop shop bringing you deals, viewing deals on your behalf, managing your property, maintaining it and they are a licensed realtor.

They do typically maintain the outdoors  / landscaping, the exterior and the roof.

Tenant shall maintain such renter’s insurance at all times during the Term of the Lease."

Thers about 20 acres of flat land, and 10 more thats on a hillside. if undeveloped means not maintained with grass than yes.

Look at your NOI (net operating cost) what would it bring in with rents after your deductions to maintain it, and then divide that into your purchase price.

I understand that I will need to purchase at least $340K in income property per the 1031 rules, my question is will I have to maintain at least $150K in new debt as part of the new purchase transaction, matching the current debt of $150K that I have on the property being sold?  

There are good rents there maybe $800-1000 for a well maintained 2 BR.