The android market lacks some features. One of them is automated updates for the android applications you have installed. Now you have to check your downloads for any updates on the market and update them one by one...
As a programmer for android I also didn't find a way to display the comments on the apps I have deployed. Didn't really get into it but it seems that this appbrain has them all listed.
You can search the website for any apps you want and schedule them for installation on your device.
On your device you'll have to install this appbrain app from the market that will sync with your appbrain online account ;-). Get it here:
And you can read a review of the app here: http://www.androidtapp.com/appbrain-market-sync/