I can see these new blocks in Admin - Modules - Blocks page, but they aren't in the "Add block" drop-down in the Blocks block. So, I've done the patch for the 2 blocks blind:

• In the case of Flickr it's a straight-forward case of adding <ul> and <li> with the "inline-list" class.
• For the Youtube block use "unlist" class; there should not be 2 links per video, 1 for the image, 1 for the text, so I think a list is better than a table.
• Because we have both an image and text I've used empty ALT text - this saves duplication.

• In both cases, we only want the ALT attribute on the <img>, the title can be moved to the <a> link.
• (I'm disappointed that the blocks use 'config_instance.html', not QuickForms (but that goes for a number of blocks - not a <label> in sight .)