I would cite the two great ones in this film: the SNIT kiss, and the Reunion kiss. I can't choose between the two, although (back to the saliva), the former is more tender and intimate, whereas the latter just lifts you off your feet.
I loved the saliva in the SNIT kiss, noticed it probably the second time also, as you did, tpe. Oh, right there on the gigantic screen -- I thought it was quite hot.
As to the whole spitting thing, I've discussed this before in a fanfic thread but haven't come to any very good conclusions. And it was discussed here, too, whenever that was. I guess I'm one who thinks just that it was a common thing to do, for men in this time and place to spit -- also because it's all dusty and stuff, where they live and work. I think it was used to good effect in all the scenes, as kind of punctuation, but I wouldn't go too much deeper than that...though if anyone else does I'd be interested. I love all the minutest symbology in these discussions of the film.
As to Ennis spitting on his hand to use on himself in the FNIT sex...all I can say is...well I think I won't say it. TMI perhaps. Just that it was a fascinating detail in this fascinating scene. (Purely cimematic/literary appreciation, you know.) (Excuse me while I cool down.)
kathy