Don't think that "Bad Romance" is any less indebted, but I think "bosh" has to be a little less...I think the word is "tasteful"?...in its execution. The three you mention after "Bad Romance" may just pre-date the concept, yeah, though I think Aqua comes closest. There's also a specific strain of bosh in which non-Europop songs are given a throbbing techno beat (the ones I think of most readily are Cascada, though to be honest I think in some ways their version of "Sk8er Boi" is less in your face than the original). The only direct sonic Scooter link that I find on Animal is "Take It Off." But there's something about Scooter's single-mindedness that I think Ke$ha has in a way Lady GaGa doesn't.