An issue is that one tenant smokes in the unit that he is in.  

He was always loud and smoking in the unit so I thought alright it's time for him to go.Finally, on the 11th, while on my lunch break, I call him and tell him I'm filing for eviction.

When I read that, I thought... smoke screen... drama... bunk!

Of special note - I don't know if your area has homestead tax exemptions but if it does this would not be homesteaded which is important for taxes.4) Go ahead and do your tenant proofing now i.e. door stops, smoke detectors, fire extinguishers, and other items some will help you liability before a tenant moves in and others are just plain cheaper and simpler to do before a Tenant is living there. 

Its not this help they think they provide.. for everyone that thinks they are helping there are 3 that are royally screwing up the deals and or in some cases that i have personally been involved with  caused the seller to lose their property because they were blowing smoke up their skirt and could not find a buyer could not close and the home gets lost to foreclosure..  

If a NNN Property goes dark (tenant moves out) or bankrupt, are you ready to search for a new tenant, negotiate a new lease, negotiate with tenants and lenders, pay lawyers, manage leasing agents, higher contractors to renovate, etc.

@Jim K.You make some valid points, a bit dark to say the least.

Residual smoke crept through the shared attic space and down into my unit.

Unless the property has some value add or it's a smoking deal there's not much you can do. 

But you can't reduce your mortgage payment when you have the roofers on the house and the HVAC starts smoking.