Beautiful. It's all working just fine.
Now, this is what's missing. In my old threads none of the "untagged URLs" are coming out because you need to run a script & tag them just as you are doing now after anyone posts an "untagged URL". Your code places the "[ URL ]" tags around,
[ url ]__untagged__URL__Link___[ /url ]
If you could do that, then... I owe you.