Bug: Permission checks in frontend inconsistent / confusing

[rixx]

When sending an admin area link to a non-admin, the page loads without error message, but the UI does not work.
Example:

• admin sends mod the link to the token generator.
• mod opens page
• token generator loads
• "generate" button circles endlessly on click

The moderator can then also click other pages in the admin menu. Some pages (e.g. reports) also load the appropriate UI, but the buttons there don't work. Other pages (e.g. Event) do not load at all.