Facebook – Is it possible to find out when a comment was liked on Facebook

Click on the "Account" drop down menu (upper right hand corner of the page) then click "Account Settings" and go to the "Notifications" tab. Go through the list of notifications and deselect any notification you don't want. Fifteen out of the sixty-six notifications represented on this page are triggered by comments.

To opt-out of notifications for treads you're involved in, deselect the six notifications that start with: "Comments after me..."

You can manage your pages by going to your 'Profile' and clicking on 'Info' on the left.
It lists out all the pages you have 'liked' sorted by category. There is a edit link on the right over there. You can remove the pages which you don't like over there.

Regarding how to show updates from the pages you've liked, I think facebook automatically hides updates from the pages you don't interact with.