Sounds like a good way of making the game more magical... And we do need wonders, those 3 or so right now are too few.
I like it, especially the Scrying Tower. like the tower with that huge eye on top of it on Lord of the Rings (No idea of it's name) Eye of the Sovereign? And YouWinBuilding? What a nice name 
Balance surely will be an issue, but im no expert in that matter.
On suggestions though... On the top of my head, I would suggest to reverse the Elementium Generator, as not only it name implies a different use, but we already have many mana at our disposal to bring even more (I have had terraforming sprees that cost me like 2000 mana and im in no way running dry) So, why not make it so it produces Elementium at a high cost? Seeing as there is no way of getting it besides quests?
About new ideas... first of all keep in mind im just throwing ideas around (so they may be too weird or overpowered to be of use, so sorry in advance)
-Vault of Minds (using magic to channel the souls of those long gone, we can recover vast quantities of knowledge) some huge boost for tech or perhaps magic, if the souls are those of wizards, so it doesn't collide with Hosten's Library 
-New Calebethon (Attempting to recreate the legendary city of old, your citizens have dug a massive cavern system below your city, fully self-sufficient on itself, but requiring of it's surface counterpart to defend it) Working like a refugee camp, but of more people, leaving that to be dtermined, it would only be a tile where the entrance shalf will be visible, so no mayor modding for underground scenery, and it fits the actual game lore.
-Crystal Temple (New scrolls left by the Titans have shown us the way to call forth a temple where great magic resides) It would be a temple like structure with four shards visible (one of each) it would count as four new shards, so it should have a HUGE cost as not to reach the Spell of Making victory so easily.
That's all I can think of right now, but if I come up with more I will tell you.
Hope to see this mod finished! It looks promising.
