so long as no-one notices it's GPL, it may as well not be.
Actually, the user must know what his/her rights are. Giving permission on a legal document and stating otherwise in a user-friendly dialog is hairy at least; I don't think the law allows that (even if I can't imagine right now what's the name of the crime, especially in English.
As for the GPL, I'm pretty sure when someone redistributes other people's work license terms must not be hidden. As a matter of fact, you are not the copyright holder, so you can't dictate the terms. And stating terms incorreclty or in a misleading way ("oh, but the loader referred to itself not to the loaded program. Wasn't it clear? I'm amazed it wasn't. I'll fix it, sooner or later") is definitly some form of misappropriation.
Not really - if it's their launcher, they cannot violate their own licence.
Again, you can claim something about my copyright and then not stand by my words. It's not copyright violation, but it's something else for sure.
/alessandro, not a lawyer