As sIKE suggested earlier, I think the mana conjurations have value in that they can allow you to cast things you know you need while still having enough mana to be prepared for whatever else you might need later on.  For example, if you're going first and you're unsure what your opponent will do, and therefore unsure what you should play, something that gives you more mana is probably the safest play you can make, assuming you cast the next category...

Creatures.  You can always use more dice as rolling dice is pretty much the only way to win, and creatures are the most flexible way to get extra dice.  Creatures (sometimes other card types) with no specific abilities beyond providing dice, fat (hp/armor), and the ability to guard things, all at an efficient cost, are what I've come to call "generically good" or "vanilla."  These kind of creatures are spread across level and school, and I believe a mage's ease of access to these vanilla creatures is something that really contributes to the strength of that mage, because they're almost always a good play that helps you win, assuming you play them at the appropriate stage of the game (early, middle, late).  Here's a list of some by level:

Level 1 - grunts, foxes, falcons, skeletal minions, firebrand imp

Level 2 - timber wolves, butchers, slingers, gremlins, sentries, alchemists

Level 3 - the holy and dark knights/archers, bridge troll

Level 4 - grizzly

After level 4, I would say it gets less clear on which creatures are generically good to cast, but from level 5 onward, creatures either start flying, gaining enormous amounts of health, and/or ridiculous abilities like Unstoppable. 

After Acid Ball came out, I think this is why spawnpoints became good; they're basically engines that make dice, and given that more dice help you win, spawnpoints reliably contribute to wins.  Battleforge works in a similar, if more restrictive way.

Of course, there are cards that are not creatures that also help; Bear Strength, Rhino Hide, Regrowth, Agony, Divine Protection, various dice/armor boosting equipment, etc.  They all modify dice in some way and that's why they're staples; things that modify your ability to achieve your win-con and deny your opponent's ability to achieve their win-con are strictly good in any deck.  Though, you'll want to make sure you have enough offense; committing too much to defense won't actually help you destroy your opponent's mage.

Basically, I see mana flowers and crystals as a way of putting you in a position to keep spending mana on more powerful "generically good" creatures (and buffs) without being mana starved later on.  The class rings should come first, however.

Uh, I want that kraken. Now.

I mean that, the card is good in and of itself (as 9 mana for that kind of creature would be, even with a few turns of delay) but the current cardpool hampers it some.  I just don't see as much support for larger creatures than hordes of level 1 or 2s atm.

It's not bad, and it does provide distraction, but it also requires support, so the distraction is somewhat canceled out.  At least, I ultimately want the creature, and I'm not terribly interested in protecting a 9 mana conjuration that does nothing until Talos comes out. 

I think pillars are more specific then that.  Nobody can beat the Straywood Beastmaster in swarm play because no one else can cast two creatures a turn while also moving forward.  Swarm works, and the beastmaster has the best aggressive swarm. 

Someone else probably has the best defensive swarm, I'd estimate druid, summon vine snappers and a thornlasher and the teleport the enemy mage in.  Defensive swarm is essentially "pit" strategy and I think pit is another pillar.

I don't think SBM is unbeatable at swarm play, or even the best really.  I'm not sure why it's relevant that the SBM can move forward while casting creatures...if anything, I wouldn't want him near the fighting since most of the mana is being spent on creatures and not defensive cards.  I usually keep a mage that is swarming at least 3 zones away from the opponent, and only after I play something like Nullify/Cloak of Shadows/armor/etc will I move it closer.  Specifics vary depending on how specifically the swarm works for that mage.

Swarm play is a lot more than just a mage's abilities; it's also their card pool and match-ups.  I think in that respect, the mage that can swarm the best is actually the Bloodwave Warlord with Necro as a close second.  They have a ton of great support cards for the strategy, like the only 2 rings that reduce spawnpoint cast costs and access to the key school-exclusive armors Harshforge Plate and CoS, though I think the Warlord's access to Conquer sets him apart.  The hardest counters to swarm other than zone attacks are conjurations (Obelisk and Orb), and being able to outright destroy them without committing attacks (or only a couple for guards) is huge.  Conquer is also just a solid play on enemy crystals or whatever.

The orc Warlord's veterans also give him an innate advantage vs other swarms to the point of making most level 1 creatures unplayable against him.  You pretty much have to play level 3 or higher creatures, which are efficient to control with curses/attack spells.  A couple Agony solve the worst offenders unless your opponent is psychic.

I'm not saying that the Straywood BM is poor at swarming; obviously that's not the case.  Based on my experience, though, a couple other mages execute a more robust swarm.  Thus, I think A. West's success at GC has a lot to do with the fact that he read the meta very well, because if you look at his deck, it's pretty straightforward.  He planned for most problems, though I think he would have been in trouble if Flame attacks/incants had more of a presence in the tourney.

In terms of "pit" strategies, I don't really consider them high quality.  It's the same vein as wall of thorns/push cheese in my opinion; exceptional if your opponent doesn't have a tuned deck, but poor if he does.

When we were recording the show, we actually typed that in the chat box. However, everyone was so on a roll that we didn't want to go back and lose all the momentum. However you're correct that her "Ranged +1" is only for non-spell attacks. However, being Fast with attack spells can be great as well. It's very hard to run from you.

Gasp, you can't say positive things about the JBM; she's just an inferior beastmaster, didn't you know? I mean, her  Wound Prey ability doesn't even work on nonliving.  I actually have to put in the nature-exclusive Kralathor and/or Light attacks in my deck.

What gives, AW  .

Other than the fact that foxes have better synergy with Redclaw, the extra 1 mana for the bird could make the difference in terms of later plays; Having Redclaw around means an increase of at least 5 dice, probably more like 8-10.  You'll want that mana open to protect your dog pack from losing a lot of dice from Banish or some other control card, or a Rouse the Beast to give Redclaw the opportunity to have a turn without getting messed with. 

Who are you disagreeing with?  I didn't say WoT + pushing is a bad finisher, even though it is.  Five two-dice attacks for 11 mana isn't anything amazing, and it's awful against anything that has any armor or aegis.

Between Battleforge/Fellella, it's pretty easy to have something to deal with attacks without having to spend a mage action.  If your opponent has no defensive enchants/equips at the end of the game, they either went all-in on creatures or messed up pretty badly. 

Zuberi pretty much covered it.  A caveat to trimming down a deck; if you are having trouble cutting cards, be strict.  If you cannot easily justify why a card is being included, cut it. 

This takes practice/experience to get right and also depends on your access to sets.  I've written a more in-depth guide to MW openings here: http://forum.arcanewonders.com/index.php?topic=12466.0