It doesn't conflict with uBlock as far as I can tell. A user recently opened a bug report about it potentially conflicting. I did testing and could not replicate. The issue could be caused by multiple extensions being combined together, but I'm unsure what that combination might be. If you have a test case that shows the issue let me know so I can investigate! FYI - I use both my extension and uBlock on some of my devices and have not had issue.

Not at the moment, but it's planned. I checked 4chan and styling works OK in Chrome, but not Firefox so there must be something specific in Firefox that's causing an issue. I'll look into why this may be happening.

Edit 11/19/2018: FYI - A new version of the plugin has been released today (1.0.10) that should fix the issue you were experiencing.

I did not, but maybe I should. I've thought about reaching out to a project like Brave that includes privacy protections in the default configuration. Either way, I would want to review the Firefox source first and determine how such an implementation would be handled. There are advantages to including such protections within the browser itself; but, the negative is that it breaks compatibility with the CSS specification standard. The flaw isn't necessarily within the browser, but in CSS itself.

Thanks for the suggestion! I plan to add a few new features into the popup area so for the time being I need to keep the icon click for opening the popup. If you need to disable the plugin because it's not working on a site, please let me know what site is causing problems and I'll get a fix out asap!