RE: Magic, lots of good ideas here.
The ones that I really like are:
1. Research spells by Book (i.e. Fire Book, Fire Level 2, Fire Level 3, Water Book,Water Level 1, Water Level 2). So that players really to make a choice and don't automatically gain access to all spells of a specific level. Sovereigns would still have to learn each spell once it is added to their spell book. Force them to make choices.
I would allow a player to purchase a spell book at start or research it later. If they purchase it at start (3 points) their sovereign would begin the game with knowing one 1st level tactical spell from that book. Have books beyond the first one cost more - i.e. 1st book 3 points, 2nd book 6 points.
2. Attunement: (Element) Talents. As was suggested by Robert Hentschke; a sovereign who has the Attunement: Fire trait gains a bonus to damage from fire spells and a bonus to mana from controlling Fire Crystals. Or perhaps this reduces the mana cost of spells from the specified school by -1.
I agree that this abilities should not be cheap, at least 10 points each. Perhaps an increased cost for atunement (elemental) abilities beyond the first one purchased.
3. Increase speed of mana regeneration. Perhaps as was suggested by having wisdom affect this (20 wisdom +1 regeneration, 30 wisdom =2 regeneration), a magic research tree and buildings that affects this (i.e. Monastery of Contemplation - +1 regeneration rate), or a strategic magic spell (Mana Regeneration, cost 20 mana, uses 5 essence, Level 4) or a Magic Rengeneration Talent (+1 regeneration rate, costs 15 points).
4. Separate regeneration of strategic from tactical mana. Having tactical mana regenerate faster seems to be intuitive as strategic magic use should really drain the soverign more.
5. Wider range of spells that does more than damage and make the spells from each spell book really different. I watched the Last Airbender cartoon series - and here the spells of the 4 elements (fire, air, water, earth) were really different. I don't get that feel in the current version of Elemental. The spells in Elemental are too alike. They need more character.
6. More Elemental Magic Oriented Buildings: Example:Water Wizards Guild, Fire Wizards Guild - that affect the cost of researching magic for a specific school. Monastery of Contemplation increases mana regeneration rate.
7. More Strategic Spells.
Strategic spells that aid the defenders of a city in unique ways.
1. Fire Elemental: Wall of Fire - surrounds the city with a wall of fire. On the tactical map this appears as a wall of fire. Enemy Units moving through the wall of fire take damage.
2. Water Element: Flood the land - surrounds the land about the city with water. On the tactical map half the battlefield where the attackers starts is covered by water, reducing their movement to 1.
3. Air Element: Wind Wall - surrounds the city with a wall of wind. On the tactical map enemy archer units find their attack range reduced to 2 or a much greater chance to miss their targets.
Strategic spells that destroy buildings:
1. Fire Element - Fire Storm - burns wooden buildings to the ground. Forces defenders to come out of the city if they wish to drive off the attacking mage and stop the turn by turn, title by tile destruction of their city. (destroys 1 title with wooden buildings per casting) - Mana 5. Wasted if cast on stone buildings.
2. Water Element - Tidal Wave - Summons tidal wave that destroys buildings built along the shore; i.e. harbor, and buildings constructed on beach titles. Affects multiple tiles. Mana 20
3. Earth - Earthquake - Collapses buildings of stone within the city, affects multiple titles - Mana 20.
4. Air - Windstorm - Destroys farming related tiles - i.e. irrigation, farms, orchards, affects 1 improvement per casting - Mana 5. Wasted if cast on stone or wooden buildings.
Strategic Spells that affect the movement of a specified ship for 10 turns.
1. Air - Favorable Winds - Movement rate for ship is increased by 1
2. Water - Favorable Tides - Movement rate for ship is increased by 1
3. Fire and Earth spells books have no spells that increase the movement rate of ships!