...is not being able to view all of a long thread at once. Under the old format, I would change the PHP variables in a thread's site address so it would load the entire thread.

Sure you can. Just go into your CP and, under Options, change your thread view.

The Thread View option allows a maximum of only 40 per page. For the long threads, I wanted to display at least 200 per page. Why? Partly out of curiousity, to see the evolution or devolution of a thread.