Literally have the cap, which is not good, that lowers your damage by a large amount. So far as SAM sub goes, no, it has nothing to do with subbing SAM, WAR, or anything else. Enhances effects are not influenced by having the stat already. You can wear Brutal Earring on any job with any sub and still get full benefits of +5% Double Attack even though it says 'Enhances Double Attack' and the same goes for these legs, so long as you wear them, you get the effects that the 'Enhances Zanshin' effect gives, the exact % however, I do not know. The only stat that 'Enhances blah' does not still grant is Dual Wield, so far as I know any other stat is given with or without already having said stat.
Why? Because they give a nice amount of Haste, you have to ask yourself how much damage you gain from using the legs you currently do to TP in vs how much you gain with that Haste. The Haste would mean faster attack, thus faster WSs, and overall more damage in the end because of that reason. The Fast Cast is never a necessity, but it is helpful, you point out the spells you cast are either super fast or you can have the mob attack your wyvern, but what about recast? What about spells that take longer? What if Aquaveil wears during a fight because you got hit while casting to often? Things can happen here which make those helpful.
This makes no sense, you do not like getting rid of accuracy, something you have an overly high abundance of since you have +60 from traits alone. That's not counting the accuracy on your gear, the fact you get to main a A+ ranked weapon as your primary weapon(unlike DRK), and the fact you are probably not fighting to hard of NMs I would assume. All in all, this -10 Accuracy should be nothing to worry about, the only time you should ever care about it is a case in which Accuracy truly becomes an issue for DRG, at which time, there are 3 other options here I gave you which have no Accuracy penalties.
What? They give you 3% Haste, which is nice, about the same as all of the other options I gave you, on top of that, they have 2% Double Attack as well as 2% Triple Attack. These stats are basically saying you get 2 more attacks for every 100 attacks you do, and 4 more attacks for every 100 attacks you do, why? Simple, 2% Double Attack means 2% of the time you will hit twice, as such, 2 out of every 100 attacks you get an extra attack, meaning, 2 extra hits every 100 attacks, the same goes for Triple Attacks except its 2 extra hits instead of 1.
Simply put, it is because they give 4% Haste as well as some potential other stats like Accuracy, STR, DEX, and so on, all of which are great stats. Now, do they win for WS? No, like every single option here except the 1 I have yet to cover, they have no real WS stats at all, in fact, this is why you should swap them out when WSing. I assumed you would be doing this, in which case, the Haste easily pushes the rest of these options to the top because the more hits you do in less time means faster WSs and higher overall damage in the end.
If you would need another piece take the hands, they are great too, but in the end you do not need the set bonus, its nice, yes, but in the end it is just what it says, a bonus. It is another one of the many things which are not necessities to use the gear, and again, yes, these are not good for WSing, but in the end the damage would be higher even if you WSed in these. The reason why the damage would be higher if you WSed in these even is because on top of the
dDEX potentially effecting your
crit rate from the 8DEX these give your getting roughly 2
fSTR from the 8STR, 6 Attack from the 8STR, and STR is the modifier on your WS. If you use Drakesbane then you get a boost on crits from the DEX just like on normal hits which makes it even better. On top of all of that, the Triple Attack can proc on the WS, meaning you get a chance at your WS spiking quite high on damage if that kicks in, but since it most of the time wont its not really a primary selling point. Besides all of this which is already meaning they are fairly good legs, they have the largest amount of Haste a DRG can get on legs, and would make your
Attack Speed much higher!
I hope I accurately explained why each of these are better choices for TPing. While you do get some more damage per hit from those legs you use now, they are much slower, which means larger gaps between WSs and also slower attacks overall. Think of it this way, if you attack for 100 damage every 6 seconds, but I attack for 80 every 4 seconds. You might hit for more per hit, but in overall damage you are doing less, that is basically what the difference is between what you are using now, and what I am saying are better options.