Someone who has handyman skills and who could do rehab/handyman work, a little project management and GC type work as well under my general supervision.

In Indiana, residency restrictions are only applicable as parole conditions, and all housing for those under supervision has to be approved by the PO before one can even move into a residence, so it is obvious he is there legally. 

and that would cover grass cutting in the summer and a certain amount of their time on a monthly basis if I needed them to let in/supervise the plumber or handyman. 

An agent is someone who "hangs their license under a broker" and works under their supervision.

As the Property Manager for a landlord, do you folks charge extra for any repair projects or maintenance calls that require on-site supervision and time spent above the normal call of duty to see the repair or maintenance through?

You can do it for your own property, but not for properties you don't own unless you are a full broker.You would have to be a licensed agent under direct supervision of a full broker running the property management company.There's an enormous liability doing property management because of the fair housing fines.

She is is in the mid to south florida region and has over 900 properties under her supervision. 

I used to supervise bookkeepers at several companies, and one to two hours a day for what you have is my estimate.

I was lending money and supervising in exchange for % of profit, reimbursement of my money at 10% interest and the real estate listings (5% of 400k).

Furthermore, others can work for you under that brokers license and they do not need a license themselves, although you must supervise their work (which is just a good idea since its your license).