[Sakujo]

While foods can change the taste of semen, changing the guy's diet isn't the only way to alter the taste of it. What a woman eats beforehand can also affect her tastebuds and thus change the way she perceives the flavor. Of course, what she eats to get a better taste is going to depend on the guy she's with and what he's eating at the time. I might see what I can dig up on that later.

Oh, furthermore, yes, women with enough practice/skill can keep a guy down their throat while he comes. As far as I know, though, this is rare.

Also, if you let a guy come anywhere he likes besides on your face, I'm sure he'd enjoy it.

Edit: While I was looking for that tastebud idea, I happened across a simple and very effective suggestion for women who want to deep throat: Once your guy is really worked up, lie back on your bed with your head over the side so that your mouth and throat are in a line and help him slowly and carefully insert himself into your mouth and throat. Make sure he knows to try to keep his movements slow and in a straight line, then let him thrust back and forth. When he feels like he's going to cum, if he pushes all the way in he'll be past the woman's gag reflex. This requires the woman to keep her throat relaxed and to fully trust her partner, who must be absolutely careful not to hurt her and to be understanding if she doesn't want to continue trying at the moment.