I've never spent money on Spiral Knights, because I don't personally like paying for acceleration. I don't have a problem with games that offer it as an option or players who take it, but I don't like to do it.
However, I have no such problem with paying for content. As such I am happy, in principle, to pay for expansion missions. I'm not entirely sure if it is wise for OOO to segregate paying players into different areas than free ones, and I think that $4 for (what I'm told is) about 30 minutes' worth of new content seems a bit steep, but that probably wouldn't have stopped me.
But untradeable and obviously game-changing weapons, available only to paying players?
That's just reprehensible. Now I feel like I'm being bullied into buying the expansion content. And I don't see any way that game balance could NOT suffer as a result.
And, more important to me, personally, that's just terrible game design. I'm a game designer myself, I care a lot about craftsmanship, and just knowing that this game did something so awful reduces my enjoyment of the whole thing.
So you've just made the first SK release that I would actually have been HAPPY to pay you money for, but now I can't, because I refuse to reward such a decision.
If you want me to buy it, add (non-binding) recipes for crafting the new weapons. It's even OK if they can only be obtained in the expansion mission, as long as players can sell the recipes on the auction house. And I'd prefer it if you stopped giving 5* items away for free as mission rewards and reduced the mission cost appropriately, so I don't have to feel like I'm buying the items, but I'm even willing to compromise on that point.
But you can't sell raw power if you want my business. Micro-transactions may still be in their infancy, but they're old enough that you should know better by now. Selling a direct tactical advantage is not OK.
I agree with all of your points, EXCEPT the following:
"Selling a direct tactical advantage is not OK."
While it might not be okay from a morals perspective, it's okay from a business perspective. That exact thing right there is what has people spending hundreds and even thousands of dollars on Wolf Team, which is developed by Softnyx. Only there, there are about 20+ weapons and 16 sets of armor that give a HUGE advantage over non-paying customers.
Here, you have a bomb and a hammer, which are mostly only overpowered in PvE. They make the shadow lairs a LOT more manageable. I really only bought the missions for the missions, but was pleasantly surprised when I saw that I could directly craft a 5*, 3*, and 1* piece of armor, and immediately obtain the new weapons. The Dark Retribution is easily avoidable in Lockdown and the hammer isn't that easy to control, but it's insanely powerful if you can master it. It's also the ONLY pure-elemental sword (hammer), it being very comparable to the toothpicks in the game now.
Now then, these weapons are flexible, powerful, and offer up HUGE damage-per-second opportunities, but I still don't see them as terribly overpowered. Why? The brandish has an overpowered charge attack that allows for corner camping. This doesn't.
The DA has a charge attack that does EXTREME knockback to tons of enemies. This new weapon (hammer), at the most, can only propel you four squares away from enemies. It doesn't have a ton of knockback like a DA and it's charge attack is basically a double Troika AoE blast with half the knockback, leaving the user to be incredibly vulnerable to attack.
For its incredible offense it adds a very risky play style, which is why it should do the damage it does. Now as for lockdown, I think the damage there should be toned down a bit to make this weapon a bit fair, but even there the toothpicks still run rampant.
There's my analysis on the hammer. Take it for what you want, but yeah. Selling a tactical advantage works, but these weapons don't give much of one, so OOO isn't really doing that too much.