For instance I feel for a decent modern system with the premise that Elemental is written for, I'd like to see a system where:
1. The tactical and strategic systems are completely separate, with whatever power source in one as separate in the other. This would allow more combat spellcasting without sacrificing any build up for summoning/enchantments on the strategic level. This also separates the research of each so one could specialize in combat mages or strategic magics and the power sources for each, which would make magic take a larger share of the game play like it does in the title of the game. I'd especially like to see the focus of the shards increased so that enchantments and summons and strategic choices are limited by the shards inside a channelers control than the pure essence of casters.
2. I'd like to see more basis in the tactical game for magic based on the kingdom/empire choice. For instance each side starting with an attack spell of life or death (respectively). This spell would be cheap and more powerful against opposite forces, while less powerful against your type. For instance 'Life blast', 2 range, 0 mana, Half int damage, quarter int to any kingdom unit, full int to any empire unit. This appeals to me because it would put the at odds nature of Empires v Kingdoms into more conflict when you know you're more or less powerful against them.
3. The ability to purchase the all four elemental spellbooks at the beginning is too erratic when compared with the randomness of finding more crystals, and when you are able to research other spellbooks in the tech tree but not the elemental books you didn't buy at the beginning. I think this represents less of an issue as an opportunity as the game also lacks any epic feel when the great and powerful channelers finally face each other. Perhaps if a sovereign could only buy one elemental spellbook at the beginning of the game, but killing a rival stole their book, this would reflect the support of such a major enemy. Perhaps even the choice of element comes from faction choice, lending a tad extra flavor to each faction.
4. There needs to be some differences in the elements and schools of research. Opposition of the natures of magic are traditional, Death to Life, Earth Air, Fire Water, Magic v Nonmagical, though I think equal and opposite benefits might be a little stale and ripe for a new interpretation, such as fire strong against water and air but can do little except cause damage. water strong against fire and stone in similar fashion, but air might have the most variation while weakest against the other elements. Further the influence of the natures of spell types must be balanced and distinct. The foundation as I see it, Earth, Air, Fire, Water, Life and Death, are set in stone to the story concept. But I wouldn't cry seeing Enchantment, Combat, Summoning, and the rest be dropped even as concepts. As it stands with the loss of the summoning book for balance from 1.0, I wonder what was in it as so many of the summons are to be found in the elements, life, and death books anyway. Right now only the bear of Natures Ally is missed, and it has been locked until significant magic research opens that book, so significant that by the time it is gained it is lackluster. I think I'd rather see the enchantments and summons, and hopefully once we get them illusions, more mind effects, military strategics effects, necromancy, and more, be shuffled back into those six domains or combinations. For example Natures Bounty currently could be as easily an life magic or an earth spell as giving it to an enchantment domain. Rare is the spell that couldn't be fit into one of four elements and life and death, and normally justifying it creates two or more identical concept spells with different names and different specific details.
5. While I cringe seeing magic too systematic and written like a science of the game world, I feel it is especially bad to have magic appear so blandly methodically while researching lost techs is rather more erratic, which I find more interesting. Perhaps make learning the spells more erratic by copying the tech system. One choses to research magic from five branches, Life/Death and the four elements (not all active if something like 3 above is revised). Then once level 1 is researched, a selection of the possible level 1 spells can appear. Level 2 offering more of the level 1 and some level 2, research level 3 offering unchosen level 1, more level 2, and a couple level 3 choices. Further deepening the depth of spell choices is to keep some spells formerly of the enchantment, combat, etc books become tech magic researchable books of named past wizards and cultures, and scrolls found in questing, that unlock spells or just increase likelihood of rare spells to appear commonly. A system like this would also support having the crystal of x element in your control adds an extra point to research of that elemental branch of magic.
6. The look of the spellbook. Fairly minor stuff but as essential as icing on a cake. Perhaps if the spell book border could be made to change color/art as the research of the chose element and life and death, are researched/pursued. Perhaps the number of crystals a channeler has shrined becomes how many and what color crystals appear in the bordering.
Those are just some of my random thoughts.