Yes, the forum software here isn't the best (it's better then Reddit though) and I do use any opportunity to bring up that vBulletin is pretty much the best. I don't think Bethesda will change it though. I use the BBCode button on the top left of the post control panel like others here too. You can also click on the gear image on the far right othe the toolbar and check the "paste as plain text" option which your profile should remember.
Anyway, my gripes with this forum software:
When using BBCode mode and the editing field is not in focus your text darkens to near invisible levels.
Script heavy main page takes forever to load.
Community board (off-topic) lists "hits" an not new posts.
Hovering over threads opens a massive pop-up containing some profile info on the OP that intercepts clicks taking you to their profile page instead of the thread.
Thread preview uses scripts and must load instead of being a simple hover over thread for non-obstructive preview.
This place somehow unselects dictionaries in Firefox.
Paste formatted text turned on by default.