They create a few minor annoyances at every encounter with them that will create a Pavlovian response of dread every time you see their name.

I was starting to wonder if I was being an annoying renter.

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. 

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 that isn't an option for annoyance reasons, start by sharing your why, and you claim 100% returns which seems a bit high so be prepared with accurate numbers and data to back up your why.

There's no way I would spend thousands to replace carpet that is only six months old unless it had an odor that would annoy the average person.

Being on the receiving end of a lot of unwanted letters and phone calls is annoying, think telemarketing on steroids. 

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

If you were to win a case like this (which I hope you don't) landlords can begin to ban their tenants from smoking just like bs city ordinances that ban people from smoking in public places (like bars) which is a true annoyance;and bring those same kind of bs rules into real estate.

I found it extremely annoying.