The live preview seems to be useless for longer posts, after some points (did not count the letters) the parts written later are faded out and remain hidden. My quick'n'dirty solution is to write my posts elsewhere (notepad++, midnight commander etc) and copy'n'paste it here.
The forum software is really slow. After changing the category, it will render all the topic messages every time. Why?
Enabling the "Hide Topic Messages" setting on the right side does not work as expected. Rendering all messages in a first and hiding all unnecessary parts in a second step is a waste of time on both sides.
The counters on the right are a little bit strange. All topics are listed with 4 digits (9761 in the moment) and behind the Mercury-category "Community Discussions and Support" the couter displays 2.23k.