Please, in the context of Perl at least, expunge "pointer" from your head. Perl references are simply not pointers. Yes, there are pointers under the hood, but thinking of them as pointers will just make your brain hurt more.

Yes, you can nest scalar references, but it is extraordinarily unusual to do so. Again, don't think about pointers. In other languages it can be useful to use multiple levels of indirection. In Perl you can end up with convoluted data structures containing a wild mix of references to nested data of different types, but that seldom turns into nested references to a simple scalar.