membership registration

We installed membership plugin but have the following questions:
1. Can we create custom fields in user registration?
2. If so, how do we connect the custom fields to the database?
3. We wish to create a terms of service check box which must be checked off in order to register. Next to the check box, we want to add a link which will go to our Terms of Use Agreement. How can we do these things? Note: We have seen your terms of service plugin. However, we do not want to use it because it has a scroll down.