However, if your PM is hiring lawyers to harass you, they're clearly litigious and I would question whether it is worth fighting them.

No harassment but mutually agreeable.

How many sellers do you need to harass with multiple mailers and shady desperate attempts to get them to sell their house to you?

Assuming you and/or your tenant haven't already done so, you should tell the neighbor his comments and behavior are not appreciated and considered harassment at this point. 

Now consider thissending 1000 mailers.100 people see the mailers and you get 40 people interested and 10 respond immediately.Since you didn't harass them the other 30 interested simply needed more time and eventually 15 of them will naturally get back in touch with you at a later point.

Rightfully so, landlords try cracking down on non-residents taking over the unit but the tenant claims harassment and the courts are so tenant friendly its ridiculous! 

You are not in such bad shape if a balcony rail breaks and your tenant dies hitting the concrete sidewalk, but if you are hit with some sort of sexual lawsuit, retaliation,  harassment, or discrimination then you are getting sued, personally, not your insurance company and you have to pay the attorney fees from your pocket to defend yourself unless you have inclusions in your policy for those types of lawsuits.

He started harassing us about giving him the documents with my partner’s social security number and we brought up the fact that he did not know at this point if he was going to do the deal.

She told the police officers that she did not have a key or my information(which is not true).I now believe she was subletting the property.She claims that she has been harassed by the neighbors, and she is asking to terminate early.

So naturally, you will get a pissed off homeowner because he/she is being harassed with letters and phone calls.