Maybe to ensure waterproofing? 

And ensure that the tenants have mattress covers on their bed and wash all clothing in very hot water.I have treated a few units with the above items.

If this is going to be a rental then you want to ensure that there is nothing that pets can smell that humans can't.  

You don't want to tie up their property without being able to follow through.You can avoid that situation by ensuring you analyze your deals correctly, meaning you value them (ARV) correctly and analyze the rehab costs correctly. 

There are numerous posts about ways to deal with that and ensure a smooth transition.

Here are a couple examples:1)  Looking for a Mentor - You could provide free labor or your time to an experience investor in exchange for learning the ropes. 2)  Looking for Deals - You could ensure you have all your ducks in a row and can close quickly.  

It essentially rewards the tenant for their bad behavior and then ensures they are more likely to pull the same stunt with the next Landlord.If they violate the lease, hold them responsible.

It's not difficult to learn and then you should practice it regularly to ensure you've got it down.

- Upon sale of the asset down the line, are you in a higher position to be audited given they may ensure you are using lower basis or is it the same as every other return after the 1031 is over?

Once they were done, we got a call, checked them out to ensure they were done properly and then the lawyer released the funds to her.