- Post form doesn't clear after you make a post

- Fake navigation that updates the page content and adds a history entry without actually navigating to a new URL is bad UX, especially since there is no indication given that the page is loading

- Hovering many buttons doesn't change the cursor

- Pagination buttons change color when hovered but an ugly border-radius shows up

- Currently active pagination button at the bottom of the page has the same background color as its parent

- "Back to top" button

- Reply button should be duplicated at the top of the page, I had to search for it initially

- Usernames don't respect capitalisation despite the signup form showing ectoBiologist as an example

- Long overflowing signatures capture scroll attempts when attempting to scroll down, just hide the overflow and users can fix them to be an appropriate size

- Permalink showing the post in isolation is not useful, it should link to the thread in context and jump to that post

- Clicking the buttons in the editor doesn't highlight them until after you type a letter, causing confusion if you clicked italics before typing anything creating an italics state which you can't backspace out of (I'm not sure the editor is salvageable, but the forum isn't really either)

- Raw editor in Markdown/BBCode

- Spoilers

- Links back to parent subforums from a thread

- Both the display name and username being part of the same anchor feels bad, better if only the username is a clickable link, I would also make the avatar a link

- "Recent post" titles on the front page do not underline on hover

- On the subforum list, post titles do not underline on hover

- On the subforum list, topic and author anchors fill their entire cells, better to make the post title, username + avatar clickable links only

- On the subforum list, an effort was made to trim the preview of post content shown under the title, but on smaller displays it still wraps filling multiple lines, better to keep it to a single line (you could use text-overflow: ellipsis)