I really appreciate this guide and refer to it frequently as I'm raising my Gren up. Having a Dragoon, I've fallen in love with Crit Damage and so I intend to get a light set for my Gren (I cannot do a CP set--it's beyond my ability).
I have more to add. Being only 44 at this point in time, I feel that I haven't exactly gotten into the Gren rhythm just yet. I did defy a few things from your guide in interest of experimentation with the skills (I personally find grenades fun though your point is very sound and I might be willed to drop them when I reset later on). I also want to ask about stepshooting. It's not something I see discussed often and I realize it's somewhat of a trade secret. Is it possible only to do this with ridiculously high attack speeds? How, precisely, do you do it? I have heard that it's as simple as pressing x, lightly tapping a movement key, and repeating. Perhaps my PS3 controller is interfering in doing that? A brush up would be very nice.
As Sharp said, Adrenaline is good enough. I always cast it with my guild skill, so thats +45% aspd if I remember the numbers correctly. The precision at which I can cancel the animation and shoot again varies depending on the day. Sometimes I can have it near perfect and never move while other times I'll accidentally dash x. It is pretty simple to do once you get the muscle memory for it, its simply alternating between moving and shooting. Down and Up or Left and right to stay in a single spot.
So what you want to do is move the least amount as possible while canceling your shots. I don't remember how I picked it up, I guess I just found it out simply by playing and over time it's become second nature to me.
Regarding H.E. grenades, they may have more potential in the future if you can get them to level 8+. They're not entirely bad right now, but even with my current build (Not same as guide) I don't have the SP to get it.