But they insist that the numbers are correct, even offer to use my own dialer where I can listen into calls besides seeing the call logs.  

Currently the heat/ac situation is electric baseboard heat and window ac units that my realtor is insistent should be taken out and I should have mini splits or a furnace added instead.

Your call.I have been hired by sellers to list/sell/handle the transaction when the buyer looked like they would be someone the sellers had a previous relationship with....I told the sellers they could make me the "bad guy" if something came up the sellers wanted done but were hesitant to insist on because they knew (or had a previous marriage with) the buyer.Best to you! 

Any potential buyer with an IQ above 50 will insist that these are replaced or they are given a credit. 

If I were to purchase a SFR from a consumer I would INSIST that they employ an attorney. 

I usually tell them that the process is similar to booking a vacation rental that happens site unseen but if they insist I’ll schedule a walkthrough with my cleaner.

I hate to call people out but the gentleman above refused to provide adequate insurance coverage and insisted on pounding on my processor until she broke down and cried one late afternoon. 

Poor managers fail to make repairs(or insist on them to owners), fail to followup on cleaners and fail take care of guests, therefore the reviews tank impacting bookings/ADR.

As stated before, certified mail to the correct address, would be the minimum most courts would accept.If you insist on doing this on your own, take a breath, and re-read what has already been said here.

I would tell him to kick rocks while insisting that he vacate his lease.