Those settings aren't in the registry, it is in an encrypted file in the same directory were your emoticons and all are...
The problem is that this encryption of that file depends on your account. Changing your account means that msn messenger can't read that file again...
The file is called map.dat... it must be recreated, and the only safe way to do that is to add all your emoticons, DP's, backgrounds again, just like you said: rename them to .png and add them again...
The shortcuts are also stored in that encrypted file... So you can't save them either...
Now, there is a program somewhere (www.mess.be ?) that can "backup" all these things and readd them again. You could use it, but in fact, it also adds the files like you will add them. But it also doesn't "backup" the shortcuts, so that's no solution either...
Why nobody made a decent working backup/re-adder? Because some people can decrypt map.dat, but as far as I know (from reading various forums), nobody has succesfully encrypted map.dat again; MSN Messenger always refuses to work when they try...
(^^ info from msnfanatic)
So, in short, or use the backup program I mentioned (which I don't know the link for, sorry) or add them manualy. But either way, the shortcuts are lost...
EDIT: I believe I found the "backup" program:
http://www.sherv.net/article78.html
But also a small warning: Many programs (all, except very old ones) from sherv.net have not-optional, bundled adware in the form of 180solutions adware/searchbar/whatever... So be warned...
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