Where can I find button images? So that I can edit them or make my own. Im guessing its somewhere in the .mpq file. Will firegraft recognize the new button image after it is changed?

The path in the .mpq file is unit\cmdbtns\cmdicons.grp. However, it might be better to just use the ones that come with Firegraft, as I believe that they are somewhat different. You can find it under the same path in Firegraft's data.mpq