I agree with previous posters that it gives WAY too much control to the model. I also disagree about putting terms of payment, especially the commission over a period of time, into the model release. Frankly, I am opposed to paying a commission to a model period. Payment to models should be a one-time deal, specified at the time of the modeling session. Given how hard it can be to get models even to show up on time, let alone provide you with contact information valid beyond the day of the shoot, I do NOT want to have a contractual obligation dangling out there for a three-year period. Because of the nature of showing work in a gallery, it might well be two or three years before you actually show or sell the work. If a model hears nothing from you for three years from the date of the shoot, and then five years later sees their photo in a book or a gallery, how are you going to prove to them that you didn't stiff them out of three years' commission, and more to the point, how are you going to prove to a court of law that you didn't, and aren't subject to punitive damages? That's all-around bad mojo. Just pay them whatever you're going to pay them. Specify that in a separate agreement.
The same goes with the "provide digital and analog copies for their use" bit. I have no problem with providing copies of work to models for their portfolios. I am not going to give them unlimited rights to reproduce without some degree of supervision from me - I don't want them taking my work and turning it into posters they're selling on Ebay.