This works quite well.
I have two issues with it though.

Firstly, when dragging a link, may I ask why it needs to load the extension's internal extension.html page to redirect to the webpage it's supposed to open? (This seems to prevent certain links from being opened correctly.)

Secondly, please add an explanation for each permission separately, as to why they are required for the extension to work properly.
(In that context, please avoid adding little stuff in a way that needs additional permissions, unless it's *absolutely* necessary. They should then be enabled on demand, not from the outset.)