Wizard being the best at magic, seems very thematically 
Um, there's a difference between being the best at magic and being the best at magical combat. The wizard understands magic so well that he can control it, hence his great access to mana and metamagic spells. That's not the same as having a ludicrously high innate channeling, for instance, or being overpowered in arena duels in general. Fortunately the Wizard does not have ludicrously high innate channeling, and I have myself narrowed down the culprit to the wizard's OPness. Turns out it is the tower. I'll explain in a couple paragraphs.
If the description on the main site describes the wizards' intended playstyle, then wizards have NEVER played as intended. They were probably OP since the very beginning, first because of their superior access to dispel and teleport, and now because of wizard's tower. The fact that they don't pay triple for anything either exacerbates these issues that already exist, or it allowed them to be problems in the first place. I'm not sure which.
I played a long time with only the core set before buying an expansion. Back then I used the wizard for mana denial and teleport/dispel supporting the slow, strong creatures. The training in air/fire was just there for the ocassional attack spell and nothing more. I think that was his initial intend. It's only after the expansions that he became the boss he is right now.
Also, there weren't that many attack spells in the core set. No forcehammers/hurl rocks/hurl boulders/acid balls/... Fire/lightning was the only thing in there and knights were the only guys with +2 for lightning so there was no real reason to use fireballs when you were an air wizard. When playing the wizard you had a 1 in 3 chance your opponent was a warlock, who's creatures can handle fire, so actually there wasn't even a good reason to use the fire wizard in general.
So, no, the wizard was really not overpowered in the core set. His spawnpoint was already very strong but really nothing that breaks the game.
Yeah you're right, my bad. Also, I have completed my Frugal Fire Wizard (core set x1 only) and will be posting it soon. I think it's at least fairly viable, but I don't think it's OP. And it doesn't seem like his access to elemental attack spells is really a big issue without the wiz tower. The Frugal Fire Wizard does not have acid ball or surging wave, and he only has 2 flameblasts. He has 3 fireballs and a single geyser though, and he has two zone attack spells which are full actions and therefore wouldn't be usable by a tower. Aside from that he's not missing any important utility spells. Acid Ball and Surging Wave are pretty good, but those two spells are not powerful enough to make wizard OP on their own. In addition, most of the fire attack spells that wizards use come in the core set, now that I think of it. And teleport and dispel also come in the core set. Therefore, his not paying triple for anything isn't the problem, and his superior access to dispel and teleport isn't the problem. I don't think it's the number of attack spells he has access to either, since his spellbook points are still 120, and the Frugal Warlock probably devotes a fairly normal amount of spellbook points to attack spell (15 points; if I had included 2 acid balls, 2 surging waves and another 3 flameblasts and taken out the third fireball it would have been 24 points). That leaves the tower. I'm thinking that the best option would be to pick at least 2 of the following options: make the tower epic, increase its level to 3, increase its mana cost to 8.
I predict that if you just make it epic, that will make the card no longer OP. It might still be an autoinclude though. If you increase the mana cost to 8 or the level to 3 on top of making it epic, I predict it will no longer be an autoinclude for wizards. Still will be a good card though.
I'm actually kind of hoping for an errata to the tower, since it's made the wizard OP for way too long, and any block format that uses Conquest of Kumanjaro is going to be dominated by wizards forever if they don't. Furthermore, I'm not sure it's a good idea to keep the wizard OP for much longer. I don't know how many sets it will take to make the tower no longer such a problem, but this has been going on almost since the beginning of the game...
