Food: They need foods with more fiber. Try clover, grass, plantain, dandelion if you can get them from chemical-free lawns. You can also add timothy hay, chopped and soaked, into the food. They'll need calcium supplements. Reduce or eliminate the tomatoes. You can also use some endive, collard greens, etc.
Breeding: Mine breed from late March into May/June. The male remains interested for awhile after that, but the females don't. In fact, the females are rarely receptive.
Hibernation: I have to hibernate mine indoors because it's too cold and wet in the Midwest and the ground around here is a hard clay that they cannot dig into.
You should check out the Russian Tortoise group on Yahoo. There will be people there who live in your region and can tell you if it is possible to hibernate outdoors.
Basically everything I know was obtained from reading things on the links I posted below and some Tortoise Trust publications.
Good luck!