They could just buy a letter online for $20 or they could fabricate a letter.

If they don't have cause, they'll fabricate it if you look like you have some monetary value they can go after.

Since we declined to renovate the basement the tenants now want to put down a roll of carpet for some padding and maybe hang some nice fabric on the walls to cover the insulation and wood studs so that they can create a little play area for play dates at their own expense.What do you guys think?  

I am concerned you will fabricate damage or other reasons to withhold.

Assuming they hadn't fabricated the document, that would be good verification.

Had some minor re-work.ETA: Probably not useful in CA, but in FL, code-compliant windows (130MPH or Installed with Hurricane Shutter/Fabric provisions) can pay for themselves in insurance costs within a few years. 

When I was a teenager, there was someone who was fired from the fabric store I worked in for behaving exactly like this. 

You're going to have to PROVE your side of the story because as it sounds, these tenants are going to just fabricate stories to cover their butts and not have to pay you. 

The margins for profit were all greatly manipulated by fabricated numbers.

I went back and read my initial response expecting it to be a lot worse and it was basically nothing, just my usual trashing of wholesaling.I know being a moderator is absolutely thankless, but this was likely because she used some buzzwords that were completely fabricated to make her look bullied when everything she was saying was about 10x worse than my responses in my opinion.