I pointed out the clause in the lease that forbids modifications and he removed this mess.

Long story short, she made unapproved modifications to the property, almost burned my house down AND I later discovered she was cooking meth.

It isn't a matter of questioning the percentage of gross rent that I should be saving for those expenditures, nor the raw amount - rather, it's about what upgrades, appliances, physical modifications, etc., truly end up being worth throwing down extra money for in the beginning. 

I know you cannot forbid a disabled person from modifying a unit if required for their disability, but are you allowed to hold them accountable for the damage done if they don't do the modification and damage your properlty?  

I think the consensus from the posts have been to honor the leases but make modifications at the end.I definitely agree with Jennifer T. on this.

You are required to make a "reasonable accommodation" for a disabled tenant, but you don't have to pay for modifications. 

We must obtain Owner approval to allow modification of the premises.

If we approve, we will have one of our contractors carry out the work ... and bill the Tenant as appropriate.If your lease forbids the tenant from making repairs or modifications to the property, then you could likely make a case.  

The cooperating broker, when acting as a sub-agent or buyer’s agent, shall not use the terms of an offer to purchase to attempt to modify the listing broker’s offer of compensation stated in the MLS Rules nor make the offer contingent on the modification of compensation.I understand they aren't changing the percentage but the structure in the MLS is based on sales price.

A modification will be a reaffirmation of the debt secured, past issues will become irrelevant.