I will add my own suggestion to the thread, that I have made numerous times (and I am deadly serious about it). You be the judge (it's pretty awful, I know):
Brainbug form. Don't care what the abilities are but would prefer if it was bizarre and somehow very strong. Brainbugs, everywhere.
Spider octowield: New spiders start out being able to use just a single combat skill. As they level up and become accustomed to coordinating their many legs, they unlock a new combat skill every 10 levels, culminating in being able to use 8 combat skills simultaneously at level 70. This will finally allow us to play as the bard / staff / archery / sword / knife / hammer / unarmed / spider we've always wanted to be!
Your ideas are actually pretty good, twincannon.
I remember I used to have an idea for a word of power type skillset. I thought it'd be cool if there was a use for poetry that you pick up in dungeons, where you can find a verse of a poem; and by collecting every verse, you get an attack, along with buffs or debuffs. I just think that'd be cool. Like a poem about a family that dies in a fie, which causes rage, fire damage, and makes the enemy slow because of breathing smoke in. It'd be fun. Then the way to use the power would be by quoting the poem. So you can use just one verses effect, or every verse for all the effects as well as an extra power up. I'm not suggesting some O.P skill, but it'd be cool if you could get this skill if you're like really high level in calligraphy and have crafted a word of power (x) amount of times, then you can just search for the poems in dungeons through drops.
When I first started playing I recommended that players could deploy ladders to scale the Serbule west wall.
LOL @HardRock
An Experimental Physics skill lineup with skills like some of the examples below. It would require a hand held miniaturized particle accelerator.
Quantum Punch - Call upon your mirrors in parallel universes to attack your target. Does a small amount of damage from several damage types (5 fire, 5 ice, 5 crushing, 5 nature etc..)
Gravitational Waves - AoE nothingness damage with a knock down effect.
Quantum entanglement - Piercing damage plus root.
Proton Beam - Piercing damage which irradiates your target causing fire damage over time.
you guys get the idea.