My lease specifically states that tenants will be responsible for the cost of plumbing charges if due to their negligence.

My understanding is (please double check) that to be charged with trespassing, you have to be 'caught' in the act.

., @Lisa Graesser, @Lucas Carl, with installing all this cool technology, are you able to charge a premium for rents?

We shall see if I regret it ;)I will charge 750-800 unit once I'm done.

I discovered their previous IRA custodian was charging extremely high monthly fees for mid-single digit returns. 

I put a disclosure that I am the principal in the transaction not taking a fee.. and I am buying for PROFIT or LOSS  … they sign and acknowledge that.. and if they want to sell for what I want to pay .. deal is done.if your think your going to tell someone their house is worth X when its really worth Y just so you can make a big spread that is greater than your commission or tell them your not taking a commission.. then that's your choice..Although do keep in mind most wholesale deals are distressed wrecked houses that need rehab etc.. and commission are negotiable.. there is no law of charging a higher commission for tough to sell properties.. if that is what your aiming to do.. 00I worked a builder out of a 22  duplex's he had built was having a tough time selling.. he wanted 30

Sounds like his Mom isn't out to get him and isn't charging him interest, in fact either scenario (the monthly agreement or the lump sum) it seems like she is giving him a great deal. 

In my contract, I plan to charge more for late fees if it exceeds 7 days.

seems that Chicago has some of that going around the Equity build charges by the SEC sound similar in nature.. that's one tough city to operate in..

If they put an outside space to eat that is substantial then you decide if you want to charge a certain rent per sq ft for that as the business is generating additional sales per ft.No legal advice given.