For groups that are not part of a network, every administrator can create or edit questions as well as create new custom field columns and ad-hoc questions. Essentially, there are no limits or permissions.
However, if your group is part of a network and the network has chosen to lock custom fields, you will need a special permission in order to add or edit questions pre-built questions, create new custom field columns, or add custom HTML to actions. To get that permission, ask your network administrator or ask us and we can enable it.
If you don't have permissions to edit custom fields then you will not be able to add, edit, or delete pre-built questions for your group, only view what's been created for you. You'll be able to add pre-built questions to a form or create new, blank questions using action only fields to individual actions. These allow you to create questions with fields that are only linked to the specific action you added the field to. It will not appear in the activist record and the data collected will not travel up the network. The data will be stored in the action itself. If you don't have permissions to edit custom fields, you won't be able to add HTML to your action forms either. And when you upload activists or edit their records you'll only be able to access pre-built custom field columns, rather than creating new ones.
If you do have custom field permissions, you will be able to access and edit all of these things.