Wow. Very interesting stuff. Comforting to know that my eyes weren't deceiving me 
Naturally, I have heard of Dan Margulis. I've only read the first couple of chapters of his excellent book, but the rest of it is VERY high up on my "to do" list. Interestingly he has recently revised his opinion on sharpening in the a and b channels so that now he states that there are situations in which that might actually be a worthwhile process. I'm almost tempted to sign up to kelby training just to watch his video series on there. I try to spend as much of my PP time as possible in LAB, if only for the integrity of my histogram. But curves in LAB mode has possibly been the single greatest discovery I've made in Photoshop since I figured out how the pen tool works!
If you've been shooting in HDR, then I'm really relieved that you've managed the process with sensitivity and have not succumbed to the temptation to go for the slightly tacky and easily dated (imo) "fantasy" look.
I'm another curves fanatic when working on images, although I've never "let rip" with multiple curves adjustments when Image Editing on here. Ok, that's a lie, I'll use a curve for the black point, one for the white point, one for colour casts, and one for contrast, but I mean BESIDES those (
), I don't localise contrast down with multiple curves unless I'm getting super precious about my own stuff, so it's nice to see it's in someone else's workflow too.
It's only been recently that I've even considered looking at plugins, and for now I'm just enjoying what Noiseware does for me. I've got trials of the Nik stuff, and Color Efex seems to be a very handy quick fix, but the thing that bugged the heck out of me with Viveza was that the u-point stuff (or whatever its called) doesn't seem to have a tolerance or fuzziness control - sure, it'll allow you to localise your adjustmens within a certain radius, but it doesn't seem to give you any control over what it decides is an acceptable range of colours to apply your modifications to. If you have any pointers with regards to using that plugin more effectively, then I'm all ears. Right now though, I don't think I'd consider it for purchase purely because of the frustrations I've experienced.
I don't think I've ever seen your foliage technique before. Adding contrast to the green channel makes sense to me, but I don't quite follow what you mean by luminosity blending the green channel in lighten mode. I mean, I understand all those words in a vacuum, but when strung together in that order as a concept, I'm left with about only 50% of the puzzle 
Nice to see someone else is as much of a student of this application as I consider myself to be. Look forward to seeing more from you in the future.