Now that's a silly statement, Regardless of how much hp you can potentially get, at whatever level, is irrelevant to why you would get a PERMANENT 420lp buff, esp on a tank/dps hybrid who would naturally be lacking in defenses as compared to a dark warrior. regardless of how much hp they have (yes I know how high their hp can go, got 2 warriors myself and been playing this game long enough to see nameks with their hp go over 11k in great namek form) It never hurts to have more.

Still though, taking a class that already performs poorly in damage and then making it into a dps/tank hybrid will just further gimp your character, esp when a shadowknights aggro would be generated mainly upon damage (due to no aoe taunt, or no spin, both huge aoe ability advantages that the other tanking classes have) so in end it's hard to find a good build as such, and while YOU might enjoy the build, your parties won't like inviting a half assed dps. When it comes to the giant form though and the techniques, you or I really have no input, or words that will hold weight in terms of how valuable/useful they are, other than sheer speculation, but I personally just come under the assumption that giant form isn't as useful as just staying small and fulfilling whatever role you want, esp with the restrictions placed upon you while in the giant form such as not being able to use abilities. You'll just be one giant meatshield, and you'll be able to perform 2 attacks roughly ever 12 seconds.. you won't be good for pulling during this since I believe you cannot dash, so I dunno.

I already made a few builds but trying to make a good build where you can tank well is hard, so I've pretty much left that alone. I'm not saying that in terms of being able to take hits or tank in tmq's (So far I've done fine with tanking tmq's even without healers np on mine using the Easy levelling build that I put up), but that they just will in end become a nuisance.

Still though, if I had to choose over the 8minute lp buff that adds like 320 something, plus the knockdown resistance buff, over the permanent 420 lp, I would easily take that. Life, or health, in any mmo, for any class, is generally a necessity unless you want to die fast. Later on in this game as one would expect it to progress, enemies will get harder, and hit harder. They can already easily hit for upwards of 3k in a single ability at only the 4th tmq. Bottom line, you either go for more defense to mitigate the big hits, or more hp, to be able to take big hits without getting one shot.

Edit: Also, usually when it comes to an ability like fear, combined with a class that has high defenses and hp, you wouldn't want them to run away fast, as from what I can also see, you invested in the special beam cannon, the self destruction wave(Two abiliies not good for tanking unless with initial pull), and you even chose to get the 2nd physical attack in the SK tree, again in which case for all these abilities you would want to keep as close range as possible, esp to be able to make good use of the physical abilities, as they would be making up the majority of your damage esp while missing an extra 19% damage from your spiritual abilities.