A few other things to consider. Herbs, or other non-magical substances for healing, stat ups or other effects. There could also be non-magical alchemy or chemistry. Other materials to fashion objects, such as weapons and armor, out of. These materials could be higher quality alloys or exotic materials. These non-magical items that have special properties could serve as treasure and give PC's something to buy and strive for. Parts of exotic plants and animals could also serve as treasure or materials to fashion objects out of. Armor made out of the hide of a creature that is fire resistant could provide resistance to fire and still be non-magical.
As far as character abilities, replacing magic with mentalism could be an option. With 3E you could use the sorcerer and alter the lists they can choose their spells from.
One interesting possibility, if you own or can find a copy, would be to use an older edition of Rolemaster. (I'm thinking of the edition from about 30 years ago). All you'd have to do is remove Essence-based magic and everything else would be there for you.
