So I've been around a while. And I've written a lot. Here are some of my... nicer suggestions? That aren't trolly bait?
How Fehzor would design the core
https://forums.spiralknights.com/en/node/74848
Tie missions to the arcade in order to balance progression and redefine the game!
https://forums.spiralknights.com/en/node/95121
How balancing works- they're long but worth reading
Armor/Weapons
https://forums.spiralknights.com/en/node/80053
And here are a few ideas on actually implementing this form of balancing...
https://forums.spiralknights.com/en/node/111840
Materials too-
https://forums.spiralknights.com/en/node/122528
https://forums.spiralknights.com/en/node/110363
Swords-
http://forums.spiralknights.com/en/node/107003
Bombs-
http://forums.spiralknights.com/en/node/113191
More places to farm rads
https://forums.spiralknights.com/en/node/112706
A fun new weapon- the whip!
https://forums.spiralknights.com/en/node/104548
Another techy sword- status injector
https://forums.spiralknights.com/en/node/112898
Shapeshifter enemy!
https://forums.spiralknights.com/en/node/84982
The most important of them all- Pizzas!
https://forums.spiralknights.com/en/node/112799