Catergories in marketpress. limiting and updating

Hey team.

2 questions.

1. If i set up categories each new site that is set up in my network inherits these unsing new blog templates. when I want to add categories do I have to go through and update everysite in my network or is there a global update?

2. Is there any way of limiting how many categories a new site owner can pick for a product.. at the moment they can pick every category which isnt cool/

Thanks!

2.