Suggestions Rated 5 out of 5 stars
Sorry correction for suggestion 1 and 2 I meant right/left click on your icon not right/left click on the main page.
1. No context menu make mouse left click on your icon to translate selected text.
2. Make mouse right click on your icon to translate whole page.
3, Toolbar Icon to reflect language flag e.g show British flag instead of your icon when set to en.
4. Add settings as options in add on manager.
5. Make a toolbar button ( I know you can move it but it doesn't look like a toolbar button like the default Firefox buttons).