All these changes sound great and like they will result in a much improved system, something everyone is looking forward to.
As most people have stated I have concerns about the spellbooks changes unless you intend to do something like this:
1) Make each Spell book into their own individual tech tree within magic, thereby forcing a player to learn level 1, 2, 3, 4, 5, 6, 7, in order to get those high level spells that we will want .... along with:
2) Make magic scale in power and usefulness better so that we want to go for the high level spells since they will give us something to look forward to and maybe even drool for.
3) Give each spell group their own"flavor", referencing MoM (the spiritual predecessor of E:WoM) I would suggest something like a system where each spelltree has certain similar themes, special effects or types of spells available earlier, later or not at all. For example:
Earth - Early gain of summoning of minor earth creatures, A focus on single target spells and defense / food
building spells
Fire - Early gain of short range direct damage spells, Creatures that are available are high damage dealing but
low health, spells which enhance offensive capabilities and metal mining ability
Air - Creatures that are of higher movement capacity, Spells which tend to have more random but intense effects
(i.e. A storm that strikes 5 random locations with 3 space of the target space dealing huge damage to them
and stunning the targets), Spells that have non random but very low damage effects. Movement and ranged
weapon enhancing spells (including the caravans on roads)
Water - Spells which reduce movement speed or stun targets, mostly spells that affect all targets in area of effect but
not for as severe of damage. Terrain changing spells. Trade enhancing / limiting spells. Defense reducing
/ armor penetrating spells.
4) Make it so that there is a "resistance" or "magical defense number" that is given to all units, this will be a base number that is further enhanced by the number of levels of spell research in each "spellbook" up to the amount of essence of the highest essence hero in that stack. This also makes it worthwhile then to have high essence heros in different stacks and changes the synamics of multiplayer games based on what spells those players around you are researching and which mana are available to hold for casting spells.
Using a system similar to this would give spellbook research meaning and change the replayability as well as enhance the mutiplayer aspects in my opinion.
