Hello Greg,
The birthdate is important so that when rostering players the site can filter by birth year.
The hometown field is there for historical reasons - the first association to ever use the site was a zone AAA centre so they wanted to recognize the home centre for their players. For associations who don't have players coming in from other areas it should be easy to just add a hometown column if doing an import, and if adding players manually there is an option to set a "default hometown" in System Administration -> Season Defaults -> (select season) -> Registration; and by setting the default you won't need to type it in. The display of the hometown on the roster page is optional.
Hope that helps,
Shaun