Do remember one thing. you can reduce a great deal of the manual post-install steps by packaging a Permission Set containing:
Apex Class access Visualforce Page access Object CRUD permissions Field Level Security permissions
Then in your documentation, instruct users to create (or edit) their Site, go to Public Access Settings > View Users, then create a Permission Set Assignment on the Site Guest User which enables all the relevant pages and classes in one fell swoop without a bigass checklist of individual configs.