Uma Thurman said to QT when he was at her house:
"You understand me".

I can see how Kill Bill could be a "love letter" to Uma, but the truth is they aren't an item, and Quentin cast her because he knows what she is capable of.

In Rolling Stone you see a photo of him in his living room, stocked with vhs tapes of movies, action figures, posters and all sorts of other eclectic items. He's unsheathing a samurai sword, and grinning like the cinematic devil he is. That picture is worth a lot. It tells you volumes about the guy.

True Romance: references to Sonny Chiba and other films abound
Reservoir Dogs: references to Godard and other films abound
Pulp Fiction: references to other films reach an event horizon
Jackie Brown: references to other films take on mythic proportions
Kill Bill: the references are now a new film, and it is beyond debate that Tarantino can be ignored. What will his next film be?
Who cares? He's given film fans enough for a lifetime.

Baby

Don't you understand me, now?

I'm just a soul
Whose intentions are good
Oh Lord
Please
don't let me be misunderstood