A few quick points:
1) As already stated, even if the party could somehow remove all of that adamantine and transport it, no one will be able to buy it from them. My party had enough problems just trying to sell all of the loot from TFoE in town - the shopkeeps aren't rolling in tens of thousands of gold pieces. if they were, they won't be in Diamond Lake anymore. (Same goes for the iron ball problem that was mentioned)
2) There are some important reasons to run GoW - the most obvious ones being the final loot at the end, the enhancement to Zosiel's Diadem, and the activation of the Talisman of the Sphere, which can come in very handy when the party is getting closer to the end. Getting a fragment of the Rod of Sever Parts isn't a bad deal either, even if it is the largest piece.
I would have to say that the one thing that makes spells like Tasha's and Glitterdust seem overpowered is that most adventuring groups use PCs with higher stats then the game is designed around. I would guess that most PC spellcasters, even at first level, have their primary stat set to at least 17, if not higher. The game is designed around the Elite array, which assumes a highest stat of 15, with a possible 17 for racial adjustments. When all spell DCs are at least 1 or 2 points higher than the game was balanced around, it has a dramatic affect.
That being said, I don't think either spell is really that over-powered, but may seem more so in the hands of spontaneous casters because they can use it more than once. A wizard is much less likely to take Tasha's or Glitterdust, and even if they do have it, it often might not be prepared. Glitterdust loses a lot of it's benefits if you don't fight invisible creatures that often, or creatures that can't see (it's useless against Grimlocks, for example).
As pointed out above, plenty of other low level spells can be just as powerful. Web is an awesomely powerful 2nd level spell, and Obscuring Mist gives my PCs fits. And then there's Phatasmal Assailants which does 4 points damage to Int and Wis (if I remember right) when the save IS made.
Just as a point of reference, my party has 6 PCs, and with the exception of one wizard who joined after the first session, and an Aasimar PC that used the buy-in option to lose his level-adjustment (so he's about 2000 XP behind right now), everyone else hit level 5 at the end of TFoE, after killing the Ebon Aspect.
The only changes from the modules as written are that I had the abandoned mine office occupied by a band of Goblins led by a 4th level Adept, and since the encounter with Grallak had a couple of descrepencies in the description (3 or 6 Grimlock guards, depending on what you read), I made him have 3 guards that were Warrior 2.
My understanding is that most of the adventure path modules, and dungeon modules in general, sort of assume a party of 5 or 6 PCs. If they seem to be having an easy time with it, I would recommend tweaking an encounter here or there, either adding additional low level mobs, or making small advancements to bigger creatures. You can also try adding more Ad Hoc XP - for example, give some Ad Hoc XP if they bring back enough evidence to have Dourstone and/or Smenk arrested.
Yeah, I just found that in one of the other threads, but thanks for the confirmation. It sounds like something I'd be interested in picking up, except I probably won't have a chance to use the material for a long while considering I just started the Age of Worms path with my group a month ago.
While probably not the thing I'm really most interested in hearing more about, I'm curious about the pricing and content. I'm assuming that at the currently listed asking price that means its 96 pages with no ads? If a full adventure path is going to run 12 issues at $19.99 each, I'd be really annoyed if any of the the pages were going towards ad space.
According to the RAW, you shouldn't lose that bonus against giants specifically because it's a Dodge bonus and not a Size bonus, although I could see some arguments for why you would lose it (if it were a Racial bonus, then there would be no way to claim it should be lost). However, even in the light of those arguments, an enlarged Dwarf is still smaller than most giants, and its really more about a Dwarf's surefootedness than his size.
As for fighting in the water, according to the RAW (DMG - Underwater Combat), in water of that depth, you always have a +8 bonus to AC and +4 bonus to Reflex saves due to improved cover against any landbound opponent, unless they have Freedom of Movement (doesn't apply for Reflex saves).
While it sounds like you already have reached a solution, here's a few more ideas:
1) Remove the wolves in the entryway, maybe have something else picking over the corpse of one of the wolves.
2) Put in some spiders, maybe as a replacement for the bombadier beetle or acid beatle swarm.
2) Add a Choker somewhere as an encounter. For even more fun, you could make the Priest of Nerull a Choker or some other non-standard race, although a 2nd lvl Cleric Choker would be a CR 4. Combining Quickness with spell-casting is always fun.