I had a LLC before I bought my first property and am a firm believer of asset protection via this type of entity.  

Send your virtual sellers a contract via mobile notary.

I use rentalutions for my properties.I have 7 properties, 25 apts and about 50 tenants.There are a lot of roommates.I definitely recommend it as it really makes rent collections easy.Their responses are generally good and helpful, mostly via email rather than phone calls.They have a reports section which comes in useful for lease renewal reports, late payment reports, etc.I do use it to syndicate rental listings, but they don't seem to post onto Craigslist, which is where I get a lot of responses.They do have Zillow, Trulia, streeteasy, etc.

They bought a house a few miles away and I do fear the current renters after they threatened me via text message.  

Next I would like to buy as many rentals as I can, via subject to or conventional mortgages.

So, I am guessing that you purchase via a wrap(seller financing where the seller has existing financing in place) or a SUB2 deal ?

Well, at least not enough to purchase another house via BRRRR method.

Feel free to reach out directly via cell or messaging.

He gave notice on Jan 22nd via email then he changed the move out date to Feb 27th, this change was given to me on Feb. 21st.  

Even those out of state willing to chat via email or something, that would be awesome as well