As a user of current Edge:
1) The Favorites Bar shows up as a folder in the Favorites list sidebar, and doing in the list sidebar seems to work better for moving things around, in my experience. (I currently feel like favorites management is worse in Chrome Edge, but mostly because I don't like a lot of the feel of Chrome.)
2) Syncing has more worked than not for me over the years, but it's never been entirely reliable. Bookmarks have seemed reliable, but I don't use them much and wouldn't likely notice if they synced very slowly. Open Tabs have never synced, but the History of them does (and shows up in the Windows Timeline thingamajigger), and faster usually than I expected, but sometimes hit or miss. Overall reliability seems to fluctuate with project priorities, and right now with Edge work on "Chrome Edge" being the focus and it having an entirely different synchronization system, I am not surprised that reliability is especially all over the place right now.
It's not. But hey! Good news! When this Beta will become stable Edge release, all you issues will be solved!
Also, the synchronization engine is entirely different from both past Edge and Google's proprietary Chrome stuff, so all new places for all sorts of new bugs.
Switching to Chromium won't be a magic fix for Edge's issues.
But I am tired of 2 problems that never seem to get fixed and am contemplating switching to Firefox because of this:
1) Bookmark (favorite) maintenance still sucks. As one example, try moving a folder in the favorites bar from the bar to the ordered favorites list.
2) Edge advertises syncing (bookmarks, open tabs, etc.) across machines with the same user signed-in, but I have never gotten this to work.