I agree. A formula sheet won't be very helpful, especially since there are literally hundreds of them throughout MERM. Concentrate on being able to quickly identify the material and where it is located in MERM. This also enables you to quickly go over the surrounding material when applying a formula, as opposed to blindly applying it from an equation sheet.
I also created a binder of solved problems, equations, etc. I never looked at it during the exam. Thus it was pretty much a waste of time. There simply won't be very many, if any, problems on the exam that are so similar that you can just substitute numbers and get the right answer. Even if there were, you wouldn't have enough time to locate them and apply them. You must know the material! Spend your time creating a good tabbing method for MERM. I probably spent 40 hours or more tabbing MERM, but it was well worth it. These pictures show my tabbing method. It of course looks like an absolute mess at first glance. However, there is some method to the madness. The bottom tabs correspond to a subject area and the chapter they are located in. The top and side tabs then correspond to specific subjects within these areas. I also tabbed the appendix subjects and the index, although most seem to prefer a separate copy of the index.
The main key is to get MERM tabbed early and practice using it while doing problems. I also used a label maker for the tabs, since I usually have trouble reading my own writing.
Good luck.