The trending topic searches refresh every 5 seconds, which doesn't leave much time to read some of the posts. I understand I can manually pause the search. But is it possible to change the refresh frequency? Maybe something like a Greasemonkey script to override the timer?
The stream can move quickly. This is true for all searches, not just trending topic searches.
You can use the pause button (located on the right side, just above the posts as they come in) to pause it at any time. The system will also pause it for you after a while if you don't do anything, to make sure you're still there.