Access and Workflow

I assigned a custom toolbar to a user, but they see a different one when editing a page.

Access settings on content such as files and folders take precedence over settings at the user level. If a page has a custom toolbar assigned, that toolbar is used for editing regardless of whether a toolbar has been assigned to the user.

I allowed a group access to a folder, but they still can't access the pages inside.

When applying access settings to a folder, if you want those settings to apply to the content inside as well, you must select "Apply Selected Settings to This Folder and All Enclosed Files and Folders" (recursive modification). Otherwise, the new settings are only applied to any content created going forward.

I can't archive a workflow item.

Workflow items that haven't been resolved (published, declined, or canceled) cannot be archived. If you have multiple workflow items selected, and at least one of them is unresolved, then the "Archive" prompt doesn't appear.