My specific questions are: -Where do I find out what her legal rights are as a roommate in an expressively month-to-month agreement with no deposit in a home that we own and occupy with tenants? 

Ask them who's responsibility it is.This is also where the expression 'good fences make good neighbors' comes in handy.

. · Please pay extra for express mail and receipt confirmations

Seems I wrongly expressed myself,I didn't rent out this unit we bought in Philadelphia , but we rented to live in another condo in Maryland.

But you wouldn’t want that because you expressed interest in a house for you to live in.

I am trying to express I feel "shall not impose any impact fee" is pretty clear that no fees for my conversion should apply.

All have expressed interest and asked for my contact info to set up an MLS search for me. 

On the contrary, explain to them why you're reaching out, but express a genuine interest in the property, in them personally, and how they have been working/treating their tenants.

Words can't express my gratitude to you guys.After preliminary research, I can tell that a number of the homes in the town where I have my rental don't have HVAC and largely seem to be boiler heated, which doesn't come as a major surprise, given that A LOT of them are built early last century and aren't very conducive to HVAC by design.Judging from the dialogue here and further reflections with my principal contractor, I think we are sticking to our initial plan of boiler/insulation/ceiling fan combo, but once we've demoed everything that needs to go anyway (some ceilings and walls) and created a much more operable working space at the same time for installations, we are going to bring in professionals to get free quotes on HVAC and mini split systems, if anything, for future reference and negotiation fodder on the next property purchases.

From what I've read, I think sending out an automated mass text message to people who have not provided express written consent is illegal.