Is it compatible with other scripts (simfphys etc.)?

Yes it is! By default, specific categories added by other scripts have a "No one" customcheck so no one can see them in their spawnmenu. If you want to change this, use !config_spawnmenu and at the end of the menu, you'll be able to modify their name/icon/customcheck. Note that the customcheck is used only to show or not in the spawnmenu, not to manage the rights of the new category.