You will no longer be able to embed videos from other sites (Vimeo, YouTube, etc.). You can still put a link, though.
Me, personally, I wouldn't tinker on forum software to tweak aesthetic or irrelevant issues; my experience has been that it's things like that that usually break down the system and send it into havoc if it can't be done in one click on the back-end. I would stick to this principle: if it ain't broke, don't fix it!
Turns out that lkngood doesn't like to see a non-functioning unlike button after someone clicks like and wants it hidden.