A survival gate to the south or w/e of Haven that allows players to fight waves of monsters that has resting places every 10 floors.
At level 29 or so, there might be a re-colored version of the Jelly King that uses shock.
At level 59 or so, there might be a re-colored version of Vanaduke that uses freeze instead.
At level 89 or so, there might be King Tinkenzar or whatever the Gremlins' king is.
At level 99, there might be a Lichen boss.

A scoreboard is also a must!

Is there any reason why there is no sleep weapons in the game? It is the only status effect that has not been added to a weapon either by charge or regular attack. I personally think it would be interesting. It would be simular to the iceburst brandish in which you can imobilize an enemy from moving.

I think players should only be able to change the recipes for the floors they currently have access to. If a knight only has access the tier 1 floors, then they should only be able to affect the recipes for the teir 1 floors. If a player has access to tier 2 floors, then they should only be able to affect the recipes on the tier 1 and tier 2 floors. This way you don't have tier 1 knights affecting the gameplay on the tier 3 strata.

Add an actual timer to an auction rather than "short" or "long"?

Just a few crazy ideas.

Bank -

A bank that players or guilds can use to store crowns, energy (crystal or mist), or items. There could be interest on crowns and it would be great to store mist energy.

Voice chat -

Just a small suggestion to fight the insane inflation of energy prices: Limiting the amount of offers one can make to buy or sell CE and limit it to only one amount, one entry in the listing. That is, you could make 10 offers to buy energy at 5000 cr but not 2 offers for 5000, 2 offers for 5050, 2 offers for 5060 and etc. It won't totally solve the problem but maybe it would help?

The concept of achievements is nice, but there isn't really any motivation to get any of them. Maybe adding in a reward scaled on difficulty of the achievement (10-1000 crowns or crystal energy) or maybe even adding some new items that are only available by getting the achievement would be good too.

I would really appreciate if you guys would put in a practice battle room in the advanced training house. You could choose tier 1, 2, or 3 level enemies and then the game would create random waves of enemies to send at you.Also, you could choose to equip yourself with any weapon so you could see how well each weapon does in combat, if you were split between buying 2 or more different weapons like me.

A few things I've been thinking about, I'll start off with the new T1 boss, the Snarbolax.

Snarbolax:

I was watching this video and thought it would be so cool to have a 3-stage transforming Owlite Boss just like this cutie:
http://www.youtube.com/watch?v=DJrupqPqKYo