The VG Resource

I know that we can make sprite requests for the Spriter's Resource, but...

What about making requests for sounds, models and textures?

Are we allowed to request those things as well besides sprites?

Yup

As it says right on the Requests section on the main page, yes you can request most anything.
Just keep in mind not to request a whole bunch of different things at the same time or people won't want to help you with anything.

Understandable.