I suggest that the Reply option (link) should not automatically quote the previous material. Since it does, the forums will become voluminous with a lot of duplicated material. Since the quoted material is almost always directly above, it is redundant and gets in the way, particularly when diagrams get caught up.

So I suggest that there be a "Quote" link that would do what the current "Reply" does, and that ahead of it the "Reply" link be modified so that it opens the edit page, but puts the post being replied to in a separate box above the edit box, formatted as on the page. This way you can see what you are replying to, as you write, but you don't include anything more than you need to. This change to the system would be easy to accomplish, I hope. A little more difficult but perhaps not overly so would be a button to click to automatically paste a quoted version of the post into the text being written.

While I'm at it, I also suggest a "Save" button below previewed text. Saves some scrolling if the previewed text meets the writer's approval.