@Grall - Right now there is no way to customize the main site feed. This is designed to show most of the activity occurring on the site at any given time. A more personalized feed is available on your account page by clicking "Account" in the upper right corner of any page on GFX. This feed will only show the timeline of people you are friends with.
As the site grows we will probably try to turn down the number of things that get posted to the timeline but for now it seems to help user engagement if it tells us more rather than less. I will note your desire to hide "bio edits" and "friends requests." Is there anything else in particular that you or other users really don't like seeing on the timeline?
I'm also going to ask that you start a secondary feature request for this as ideally we'd like to see one topic per forum discussion. Thanks!
I was also wondering if it was possible for a user to change what appears on the main site timeline. Personally, I don't need to know when someone edits their bio or becomes friends with someone else.