Something that might help: on the left side of the timeline, there's a new icon for enabling/disabling preview bar calculations. Try turning it off, since it'll bypass the code that tries to analyze whether it needs to red bar sections of your timeline for rendering. That in itself might help speed up editing until the time you need to render the finished product.
I also noticed that heavily nested sequences can bring the program to its knees. Although I have found a work around for that one. If anybody is interested just turn the little eyeball off on the nested sequence and then you can go back and edit the original with no delay whatsoever.
With Premiere Elements 3.0 if you put the video footage in the video 1 track it is slow to respond, taking at least 15 seconds to do most things. When you put the footage in video 2 track instead there is no lag of 15 seconds, it is instantanous.
I figured out... Its the Audio hardware settings. When you have both "Built-in line input/ Built-in Line output" then the audio preview is delayed. I've set it to only "Built-in Line otput" and now it works perfect.