Thanks for your review & suggestions.

Since v1.13 the restore behavior can be set in the addon options.
Also CTRL + click toggles the behavior.
As of v1.8 there is a button in the browser action menu to just save the tabs.
v1.16 brings the ability to select any bookmark folder as the Tabs Aside folder.

I am not quite sure what you mean by your last point, feel free to elaborate here:
https://github.com/tim-we/tabs-aside/issues