Safari in Yosemite
1. Tab management is bad. I hate the lack of favicons and the dynamic width tabs. Glims used to fix this, but it doesn't work yet, so I'm out of luck.
Don't have much to say about this one. I imagine Safari will continue to work like this. FWIW, I've found that I'm using the pinch-to-zoom-out gesture a lot to navigate among tabs. It's useful now in a way it never was in Mavericks.
2. On all my applications, I set CMD+1 to Previous Tab and CMD+2 to Next Tab. Unfortunately, this behaviour doesn't work in Safari, because CMD+1 and CMD+2 are somehow hardcoded into the application and set to different things.
It will mean re-training yourself a bit, but in case it's helpful, you can jump between tabs left-handed with
CTRL-TAB and
CTRL-SHIFT-TAB in Safari.
3. All links which open in a new window, due to some bug, cause a full 1 second freeze before opening.
Yes, definitely sounds like a bug I haven't had that problem. Perhaps check back after a re-install of the public release?