v3.1.1

With this extension you can disable specific routes like affiliate, information/sitemap etc.
You will find it in Extensions -> Modules -> Disable Routes.
There you can add routes you want to disable and assign them to any of your stores.
This way you can have a second site where you can disable all the core features you don't want to use (e.g. a microsite where you disable all the shop features).
On the disabled routes the 404 page will be displayed.

Should work on all 3.x but not tested.

Please share your experiences in a comment.

cheers :)

My other extensions:
Core SEO URL
Language Editor