If you want to disable avatar, you'll have to edit open_graph_meta template and find the line that adds avatar and remove it. If you want to remove xenforo logo, it's better to revert my customization or change the default logo as documented here. My customization was so that it's possible for user to still choose the logo if they don't want to use attachment picture when they share my forums on Facebook.
Does 0.jpg always the same as hqdefault.jpg? I have kinda finished my add-on which is sorta packed with extra features requested by someone else. But for the extra feature of adding YT thumbnail, I kinda used hqdefault.jpg instead of 0.jpg.