Inquiries, expedient responses for assistance, repairs, and maintenance, frequent rate/yield analysis, etc. 

What types of "extra" major maintenance is needed in places with snow? 

There are so many threads on BP of investors in the northeast or CA who bought a random midwest property because it looked great on paper and got crushed by deferred maintenance.

Conduct thorough research on potential properties, considering location, condition, rental potential, and maintenance costs.

Triple Net leases allow the Landlord to pass Operating Expenses (primarily comprised of Property Taxes, Insurance, Common Area Maintenance, Snow Removal and Property Management) directly through to the Tenants of the property on a pro-rata basis. 

I'm wondering how folks estimate CapEx, maintenance/repairs, and turnover costs?

I got tired if that routine and went and found a smaller tax operation where my first question was -“ I want these filed on time - Can you do that?

This fee covers comprehensive services, including marketing, booking, maintenance, cleaning, linens, etc.

The way I see it is that the monthly fee should cover coordinating routine maintenance (HVAC tuneup or minor maintenance, leaky faucets and drains, sprinklers, minor pest control, etc.), but larger ticket items that may require multiple bids, permits, or otherwise could have reasonably been prevented should be handled separately and charged to the owner.

Unless you have a very high maintenance tenant or tons of old plumbing/mechanicals you can do really well by having an 'emergency list' of really good handymen, plumbers, hvac tech, etc.