I don't know if I'm just susceptible to group think or if our ideas all converge around solid principles, but I do like the thought of maximising card draw, cycling and scry effects in order to lead to more interesting, interactive and less mana screwed games. I think there is some intersection here with the reducing aggro/ changing how you design for aggro as to be honest most of the cards we've been talking about here are traditionally for midrange and control.
I think a cantrips only cube might be fun for the novelty factor but I doubt it's good design by itself. One of the mother ship articles about conspiracy talked about parlay and the other "all players draw a card" designs in the set to make sure that all players have 'action' and I think this has merit when considering cantrips etc. I think more cubes should be playing
...Particularly if you utility land draft. Re your massive card list above
Pyrite spellbomb - seems good in principle but not that exciting in practice. Might be okay if it intersects with lots of themes, like the artifact deck cards, furnace celebration, trinket Mage etc.
Akromas vengence- rarely cycled, expensive wrath, not that interesting.
Azorius charm - two colours of mana make it harder to cycle in the early game, unlikely to make you move into blue white, dull.
Carven caryatid - good card, hurts aggro, but not sure that's terrible. You might want to make sure aggro has evasion and falters
Complicate - fine, not the most efficient counterspell but that's not terrible, can be thrilling to force spike a spell and draw a card
Disrupt - depends on how many instants and sorceries you have, but likely to be too variable and will wheel, be left in sideboards
Dragon mantle - I think it's good, comes down to space and direction you want
Erebos - interesting card that makes you prioritise life gain and heavy black spells. I like.
Exclude - can be feel quite mean, but is a more restrictive counterspell, so not a bad thing, I used to run it.
Explore- fine, if a little unexciting but good to help smooth out draws.
Heartwood storyteller - seems a little restrictive and obviously symetrical, would be interested if people give it a try
Into the roil - I think most of us play this, good.
Ninja of the deep hours - I've recently added it, will see how it goes, but like that it puts a bit of proactive pressure on and helps five blue a different flavour
Aether spellbomb - see pyrite above. Might be a better colour but more dull.
Psychic vortex - give it a try, feels a bit restrictive and you obv can't hold up counterspells, what sort of deck would you play it in? Reminds me of aggressive mining.
Radiants judgement - good, like it.
Reprocess - I've never been able to get it work, I don't think the cards are worth the investment, particularly at sorcery speed.
Rerout - feels too restrictive, unlikely to be played.
Scouts warning - I quite like this, have it in my decision cube.
Shadow of doubt - if you have lots of fetches in your cube, then play it, otherwise feels restrictive and potentially feel bad.
Snakeform - I like it and am playing it. Gives more interest to green.
Soul of the harvest - could be okay, but would probably want more for that mana cost, there are other more interesting ways to generate incremental advantage at that cost I think.
Squelch - I think Jason is trying this. Good against fetches, not sure how good it is against other things.
Staff of nin - I like it but not all that powerful, I think it could work if you were taking the cube more in this direction and cool in laz's cube with his tinker package.
Symbiotic deployment - urgh.
Triumph of ferocity- I like and think could be a good addition to green. Nice mini game.
Unearth - fine, not sure it does enough though. Would prob rather have barren moor in my deck. Filler.
Wall of blossoms - sweet.
Well of knowledge - not sure how to evaluate this. A ramp card? Only good if you have stabilised or are winning?
Whispers of the muse - fine, but you're not going to buyback all that often are you? Would you rather have opt?
Wild dogs - need green aggro to be a thing, but I think you want to make your aggro more interesting and robust than this.
Whistful selkie - that mana cost... There are better things to do at 3 unless you have some heavy devotion thing going on.