I do point out that the dog crap all over the carpet is fine and the cockroach infestation is something I will take care of..I solve problem...

As-is just means that you can't sue him if it falls down after closing from a termite infestation. 

But the house has been unoccupied for 4-5 years, is infested with mold, has a lot of structural damage from water and ice due to multiple roof leaks, and the septic system hasn't been used since the previous owner passed way.The property generates a lot of interest... from first time home buyers attracted to the lower price-point.

I couldn’t even imagine the power that tenants could have if they wanted to make a fuss out of a mouse infestation, even though this is a very common issue in multi family (especially in our neck of the woods, I dealt with this myself last year…) and you have done everything in your power to try to counter the problem.

The inspectors from the pest control company did not discover this infestation under the bricks on the walkway to one of the units.  

Even if you have a secure network, your tenant's PCs could be infested with malware, viruses, etc. that cause problems.

DO NOT waiver on checking them out because ive seen some pure roach infested slobs in some of my inspections..

-Water pouring in because the Amish roofer who just put the new metal roof on is a terrible roofer-Having to knock holes in the wall so the plumber can repair the broken stack that's oozing you-know-what-Seeing my property on the morning news due stating one of my tenants was shot and killed-Having a massive tree smash a duplex-After evicting a tenant, cleaning food out of a maggot-infested freezer-Massive water bills due to running toilets-After move-out fixing all the things tenants damaged - time-consuming and not fun-Dealing with trespassers (happens a lot in C-class)That's what first comes to mind.

If I find that two of the units in my building have bed bugs infestations, it is necessary to have all the remaining units and common areas in the building also treated for bed bugs? 

A bedbug infestation?