Please note that since your snap was added to the store, we have added a number of interfaces including ones for gpg, ssh, personal-files (for accessing dot files) and system-files (for accessing files in, eg, /etc)?. Have you explored these newer interfaces and perhaps using snapctl is-connected <plug> to provide a better UX for manually connected plugs?
This doesn’t address the issue of git hooks though, and there are other snaps like git-cola that were granted classic for this reason. Note that snaps will not refresh automatically from a strict mode snap to a classic snap. If you still want to pursue classic, what is your plan for migrating existing users?