All add-ons in regular firefox are available. Same with features. I don’t use sync, but I see the feature.

I use Mull. It’s Firefox but removes Firefox trackers and add privacy settings right into the browser.

You can get it via FDroid (I use neostore client) and it gets frequent updates.

That’s not true, I have Google Play Store with my regular gmail account logged in. I have all my usual apps installed without any issue.

Pixel 6 Pro with Graphene OS