Roles and permissions

I am looking to create some custom capabilities to use in some blocks. I've been told that locks can't create capabilities; can I have a dummy module that does nothing apart from hold these permissions.

They are for a variety of things: whether or not they should see links to MIS pages and systems to book minibuses etc, whether or not they should be able to use a searchable list of teachers/students, a few other odd things.

Is there a reason why a couldn't/shouldn't do this?

Thanks,
Mike