Actually, the FT 15 is a combination of many common things... including mana regen pots =P I accidentally found that combination when my JB faded mid-raid, and no chanter was close... I started asking for "any mana regen you have" and I found myself with as much mana regen than I'd have... and all those items were usable, and easilly attainable for a level 57.
Now, I know you think motss is high end, but he's actually low tier. It has been done by pickup raids, with only 2 or 3 geared chars... but that's not my point... my point is that Traekoth IS high end on adepts. Motss would be like sludgebreath, maybe. But Traekoth is like Ulazzaria... You're gonna need really dedicated people to down it, and probably you'll fail a few too many times. And yes... Rust 1 group has SOME mobs inmune to wizards... totally inmune, which means that, for those adds, they do nothing but look cute... And poor froglocks aren't cute, even! And yes, they have caster loot. Traekoth is not inmune... is just insanely hard. WHAT made it that hard? from what you tell us, healers were oom too fast... but they were healing too many people.
I'm a cleric myself, and, usually, I take the role of Group healer (on main tank group), which means I'm in the middle of the AoE, getting damaged. But, this kind of healing is far more effective than it seems, specially, if you have padders set on meleers, and you just cast an AoE when everyone is low (or is gonna be low when heal lands). For low level raids (or easy targets) you can just go there, and burn some mana... but, on high level raids you have to time your heals, and, sometimes, this means 150 % skill, yes...
BUT that's why rewards from one of such encounters is that high. Let's take a named, for example, Scribe Athos, in sepulcher. He has almost no clean to him, and some silly AoEs... rewards from him are a little sub-par for the zone, yes, but the challenge rating for him is also lower than the zone. Now let's look at Disciple of the Order. You need hours and hours of cleaning trash... is harder if some other mobs are up, and you even have to clear a 6x pull to get to him. Furthermore, he is a multi-part event and the fight against him is actually hard (for its level). Rewards for priming this encounter are definetly over-par for the zone... but also the challenge rating.
So traek now seems a little too hard... I recall a time, when 2.0 was introduced, that Taesh was a little too hard... Was actually doable, but HARD as hell... he was tweaked, and he became like definetly TOO darned easy, so he had to be tweaked back. My point here is that Traek is hard, yes... but I still think it is doable, for someoen who has been getting prepared for him. It seems now there's another adept higher than him... which makes him second highest adept... which means that, once you beat him, and you beat next adept, you've finished with adept raiding! (can't see much point on an adept level 64 to engage, for example... and level 65 to engage would be normal raid) So, you guys are in the END GAME, but in the FINAL END GAME, which, imo, justifies it being harder than expected.
Also, after reading them numbers on the other post... 560 dps may seem high, but isn't beyond what a good healing squad should be able to heal at 57. I think your main issue was too much people being damaged, and not an optimal healing system. Also, were you using mana potions? did any of you had larvaes (or canni shoulders, but since those are pot raid, doubt it)? A good ammount of modrods (meleers can always pass one to a healer midfight) Mana potion, plus modrod makes a good ammount of mana. Did you guys had clickable nukes? stocking on Blazing veils to be mass clicked on that fight seems a good idea to me...
My point here is that traek should be really, REALLY almost unbeatable, except by people prepared for him, and them, he should be a hard fight... since you'll be doing pounders next, then, it's bye bye adepts. Grats, you beat the game. Wouldn't you be dissapointed if last fight was too easy? Cause I know I'd be. I was dissapointed at first when fire mini in thaz was easier than Fie boss (fire boss was bugged around that time). I also was dissapointed when a bug dealt 52 % damage to earth boss.. And was dissapointed when logistician drone wasn't working yet when we tested mercury.. Mostly cause, even if we won... we won... "cheating". Not that we wanted to cheat, but still... Same can be said about Traek. Beating him should make you feel like a milion dollars bill, and, in order to do that, he HAS to be hard.
In any case... what tweaking would you propose?