Little late in the game here and I haven't read through all 30 pages of this so please forgive me if I'm repeating someone, but: revenge fantasy or not, I think, is besides the point. Tarantino, at least how I read the film, is more making a point about HOW propaganda (revenge fantasies and the like) work solely from your own perspective and are absolutely appalling if you're the target of them.
So we have the Basterds, who are by pretty much every indication terrorists. They murder indiscriminately, they strap suicide bombs on their bodies, they even are flat out called terrorists at one point by Landa. But because we know, historically, their cause is just (from our perspective) (I mean it's hard to argue in the perspective of the nazis, which is why I think Tarantino chose them) - all their actions are not even just tolerable, but cheers-worthy. The movie we're watching is pretty much the modern version of the film that the Germans are watching in the cinema. I don't think Tarantino is injecting any moral judgments here, and there's little to no chance that he's arguing nazis get a bum deal in cinema. But he has talked before about always identifying with the Indians in cowboy movies, never understanding why the hell they were always the bad guys. I DO, then, think he's making a point that terrorism only seems like terrorism when you're on the receiving end, and our media is always sure to craft a flattering narrative about ourselves, which we lap up.
You could argue that's reading too much into it, but then I could counter that he does stop the movie halfway through to have a character give an allegorical reading/essay on King Kong. Even if Tarantino is not flat out asking you to do the same work with his film here, he's at least saying 'this is how I sometimes think about movies."