If he's in CA, he'll just have to pay to fly to CO to appear in court.He should gather all of the written proof of his offers to settle and take them to court and just tell the judge he's tried to settle with the tenant, but the tenant is refusing reasonable settlement offers and has demanded an unreasonable amount of money, so he'd like the judge to determine what he/she thinks is right and fair.The judge may come up with some money to be paid to the tenant, but I very much doubt the judge will say your friend should pay $4500.And then your friend may have to be ready to sue the tenant for damages after they move out, too.I do get how annoying it is to live with construction noise. 

I can't tell you how many times I went back and forth with a tenant about a good time for me to show, only to have the potential tenant no-show on the appointment, then all that time is wasted, the current tenant is annoyed, I'm annoyed, no one is happy.There are potential issues with allowing strangers to walk around an occupied property.

They may not be aware they are annoying you.

Interest rates are very low right now, and you have to send the tenants very small checks, which they may find annoying. 

If the guy is annoying you, you can be sure that the inspector is annoyed too.

I also would not assume the second cat,  the humane society could have denied them on your response (and they could be annoyed about this). 

Remember market means people who can afford the place but are annoyed/ unhappy with your management will  also leave.  

He works for the city that the property is located in and constantly keeps watch on the place throughout the day which is definitely annoying considering if I'm there doing something outside, he has to stop and ask what I'm doing...

As @Charles Carillo said, it's a small building, make face-to-face contact as you have and deliver rules and regulations and payment procedures and go over it with them and make sure you answer any and all questions they have during that visit and give them a non-annoying way to contact you (email is better) and let them know the timeframe of response.

If they are annoying me I'll ignore them for a bit,And for the record, I've never had a tenant use text speak at me.