You've got my number!
If you don't have a sturdy system, with GPU and plenty of RAM, you could experience this issue. Recall that Premiere Pro CS5 and CS5.5 are 64 bit applications and require more system resources. That said, whenever I experience performance issues in Premiere Pro (like on my MacBook Pro), I drop the screen resolution to 1/2. Right-click on the Program window and set it to a lower res.
Group adjustment? You can do a submix with several tracks and adjust them at the same time. More info on that
here. Might that work for you?
Not sure what you mean by clunky. Dynamic Link just "works" but there are some issues you may be experiencing as you would with a Motion project living in a FCP timeline. Stuttery? Render it. Need to media manage it? Substitute a rendered file for the AE comp in the timeline. Keep in mind that you can always bring a question to the Premiere Pro forum:
http://forums.adobe.com/community/premiere/premierepro_current
If you are talking about trimming with the keyboard, I agree with you. Make a feature request for that
here. Most all else has mappable keyboard shortcuts that will allow you to use a more keyboard oriented approach.
I hear you and thanks for the valuable feedback!