I didn't play in beta but came to Card Hunter right after release and have been playing the heck out of both the single player (finished the campaign ages ago) and the MP. Finally got to the point of being willing to say "these thoughts have some validity" and not just small sample size and whatnot. NOT FUN 1. Draw decks are not fun to play against (pass, pass, pass, pass...) even though I've beaten them occasionally, and at least for many of us not fun to play either. I know there's a solution coming, I'm just piling on here 2. Whirlwind Enemies and Whirlwind decide games too much. I'm not saying they're overpowered as such, because quite often they backfire. But it's not even particularly fun winning because the other guy plays WWE and deposits your warrior with an obliterating bludgeon next to their mage. It's even less fun losing because they play one card and screw all your positioning to hell. The effect is far, far too large for one card. There's enough random luck in this game without WWE and Whirlwind. I would honestly have the effect of those cards changed completely, perhaps to a mini Winds of War (WWE) and some kind of All Run (maybe you get to team dash and the other team gets to team walk or something). OVERPOWERED Nimble Strike (dash AND 6 point hit AND the ability to move and attack - effectively a built in cantrip- is just way too good, particularly considering it makes a mockery of human and dwarf racial moves. Damage and/or the move distance should be toned down). Mass Frenzy (this could easily be an emerald calibre card, from the amount of extra damage it creates- especially overpowered in combination with the aforementioned nimble strike and other Step attacks). Hacks/Bludgeons (probably a point or two overpowered, making all the martial traits a bit pointless because Hacks, Bludgeons and step moves all outclass bashes, chops and penetrating moves). Maaaaaaaybe Nimbus (not of itself, but Nimbus does enable a lot of draw deck stuff and killing Nimbus and nerfing Mass Frenzy would probably fix a lot of stuff) NEEDED A buffed Purge (draw a card, Cleansing Ray style) and a Mass Purge would give people realistic options against decks which rely heavily on attachments like Mass Frenzy, Nimbus, even Accelerated Thought, Cone of Cold and Firestorm. At the moment it seems like all the good decks abuse attachments heavily because there's such limited removal (and no removal that gains card advantage; in the case of something like Mass Frenzy, you're trading a Purge for 1/3rd of the Mass Frenzy, so. not exactly a great deal...) Celestial Koi to never return (Gods that map was annoying; just too much stuff in the way of the two sides getting to grips).
Considering you weren't in the Beta it looks like you've done a very good job of summarising a lot of things that were still provoking debate at the end of the test! From memory: Draw decks not fun to play against. They did change some of the cards that used to enable this but it's clear that they need to do more. Whirlwind Enemies destroying the tactical positioning element of the game. Not necessarily overpowered but also not much fun to play against. Really high damage melee cards preferred, meaning that Martial Skills were just used as deck-cycling cards. A desire for Purge cards to be more easily available. I'm not certain a Mass Purge was ever suggested though. I think the complaints against Nimble Strike and Mass Frenzy are mostly new but I could be mistaken. Nimbus was raised a few times but by-and-large people seemed okay with it. In short, I think this is good feedback.
I agree with every one of the OP's assessments. My preferred fix for ww/wwe and nimbus would be to reduce how easily stackable they are. Nimbus for one round is tactically interesting and can be a great counterplay. Playing nimbus four rounds in a row while sitting on the victory point just gets ridiculous (this has happened). Same with the whirlwinds really, stack too much of them in a deck and character positioning (which I'd argue is most of the multiplayer strategy) becomes a joke. I would like to see changes to rod of winds, tempest robes, duality mace, shielding token - anything that has more than one whirlwind card or nimbus on it. Those items are just designed for abuse. A mass purge that removed the oldest attachment from every character would be a perfect addition to the meta. (A purge that removed all enemy attachments from all characters would probably make frost too weak.)
Agree with some of the points: hacks/bludgeons - agree big time, would like to see competitiveness of other damage types improved nimbus - how about 'target can't use attacks during this round'? WWE/WW - make it have range of 3 around the caster?
Can we put a stop to the Frost terror as well? It's just ridiculous how a Frost deck can shut you down completely, especially when combined with WWE/WW.
I don't think nimble strike is in of itself a problem. I think the availability of nimble strike is a problem. It's on (relatively) few items and many, many people play MP without it simply because they don't have it. I own exactly one item with it, and it's on a priest. Every high-ranking warrior deck I run up against seems to have it. I think re-balancing the items it appears on would be a better solution than just nerfing it/removing it.
I've been playing this game for about a month now and not once have I found an item with Nimble Strike on it.