My phone keeps slowing down and burning battery. How can I debug performance and cpu consumption? (DHD 2.2)
The adb likely won't be of much help.  The apps need to have debugging enabled to be able to see their thread and relative performance I believe.  

I assume you've looked at the battery usage menu in your phone.  What is it telling you?

You could the hidden debug menu in your HD.  It may provide more info.  Open your phone dialer and dial *#*#4636#*#*.  Give that a try.