> The huge size of the drop-down menu.

This was added a couple of days ago to compensate for people with high-res monitors where the popup ended up being tiny. I guess it will become another option in settings…

UPDATE: Reverted to the previous behaviour, the new behaviour is now available as a disabled-by-default checkbox in the extension options.

> The huge size of the extension itself.

Since this is a recurring question I've added an FAQ entry to the extension's description. Please kindly refer to that for an answer.

> Access to browser activity during navigation.

Used to switch the extension's icon color and tooltip when you navigate from/to pages that have an override set. I could do without that permission but this way it is more reliable and easier to implement (note that extension will be able to see all sites you visit regardless of this permission, it's just more convenient to do it this way in this particular case).