Since she has no lease and you are the rightful heirs, you also have the right and ability to enter premises and ensure its safety, etc (again, talk to attorney on this).I have heard of others having some "rough types" move in to a few of the rooms to make it very uncomfortable on the trespasser in hopes to get them out.

It's an uncomfortable situation and not a conversation I'm confident of or can even predict how it will go.So . . .

If you feel uncomfortable move on to the next deal. 

At my own home I do early routine cleaning and maintenance which runs about 100$ a year, so wondering if this can be done every 6 months or every year to clean the drain pan, filter, etc. at what frequency? 

That may be hard to believe starting out but trust me it will happen for you if you do the uncomfortable work that is networking.But building your Facebook and website was not time or money wasted. 

I recently found a very good foreclosure on Homepath.com, submitted an offer which was accepted, did home inspection, and then found out that no title insurance company is willing to insure this property because all foreclosures in Massachusetts are pretty much void because they did not comply with the correct notices for one reason or another, and also foreclosing banks often did not even have the papers showing they have the right to foreclose in the first place (they lied about it in court to get through this routinely, but eventually judges stopped letting them do this).

Use the credit card for routine purchases and pay the balance at the end of the month.

In my experience, tenants rarely hold up their end of the bargain when it comes to routine maintenance.

He is clearly uncomfortable with fronting all the money.

But his article did not list them as elligible, although it didn't say explicitly they weren't, and I have read many threads where people say they purchase SFR's with commercial loans routinely.