Hey, thanks for the feedback. Those are all fair points, but lemme just comment on three since I'm finishing up other work for the Firefox 34 release.
1) I have NNL-specific icons for ABP, but they aren't being applied at the moment (fallout from the Australis redesign). I'll get to that presently.
2) I know about Restartless Restart. One limitation of all the restartless add-ons is that the icon is set by JS as explicit src attribute on the element, meaning it can't be set by the theme. However, traditional (non-restartless) add-ons can be themed, so if you identify one of those I'll update NNL to support it. QuickRestart was good, but last I checked it's not maintained any more.
3) I know what you're saying about the scrollbars, but I like the checkerboard, and it matches the checkerboard that shows behind toolbarbuttons when you click them. NNL has a distinctive style, and that's part of it.
If you want to say more, please do. Using the forum might be more convenient: http://forums.mozillazine.org/viewtopic.php?f=48&t=547498
Thanks again for the feedback. Those are all good, specific, actionable points.