Thanks for the review. Glad that you like it, as regarding the 2 issues.
1. When it comes to graphics I bet it's not that easy to find a good set of icons that will please everyone. Most probably I will try to integrate the possibility to select from a bunch of predefined icons and who knows... at some point (If I find the time to do it) even let users load their own icons.
2. I don't remember having any serious issues with Firefox bookmark syncing but I know there are reported cases when it might not work as expected (although they should be mostly solved lately). Providing a custom solution for bookmark syncing does not make much sense right now as there are already a few alternative solutions out there. I will integrate at some point an option to import/export bookmarks through JSON but this won't really solve the sync problem.
Thanks again for taking the time to leave the feedback. Sadly, I can only promise I will do something about only for the first solution.