Spellbooks on sov creation:
Below is an idea about how to make spellbooks on sov creation have a choice factor (specialist vs generalist), give some real benefit in early and late game and to allow more thought to be put into it. (since I detest the thought of removing it from sov creation and moving it to research)
(for the below I just played with numbers assuming you had say 100 points to spend on sov creation mostly on magic)
Every x knowledge levels above the level required for the spell should unlock a new aspect or significant boost to that spell, each level invested in spellbooks on creation would count as equal to a boost of y levels of knowledge in that spell sphere but cost incrementally more.
If for example x=2, at 2 knowledge above that required for unlocking a 'fire flick' spell it gains a cost reduction, 4 levels above it gains a damage boost, at 6 another damage, 8 burning effect, 10, 12, 14 damage, 16, chaining, 18, 20, 22 cost reduction etc.... each spellbook could count as (y=3) levels of knowledge so 2 fire books gives the first 3 bonuses free. Although my personal preferance for balance is that it could count as y=1 (x/2) so that 4 spellbooks are required to give the first 2 boosts (such as a damage and cost reduction at startup)... i.e. generalists capped at 3 spellbooks would only have 1 bonus to spells from any book max but would learn faster in all realms than a lesser mage. Specialists at 6 max spellbooks can gain 3 boosts to each spell upon learning it while learning how to make other spells stronger at a significantly reduced rate.
Having more choice there too would also be good, such as:
Earth (General) - 3, 6, 9, 12, 15, (15) point cost for levels 1,2,3,4,5,(bonus 6) at sov creation (45 points for mastery, 60 for specialism)
Earth attack spells 1, 2, 3, 4, 5, (10) (also 2nd, 4th and 6th ranks give a penalty to elemental opposite defence/resistance) (15 for 5 levels of attack - 2 defence/resistance, 25 for specialism -3 to defence/resistance)
Earth defence spells 1, 2, 3, 4, 5 (similar to above but penalty to magic attack strength)
Protection from earth 1, 2, 3, 4, 5 (15 points total, point cost -1 per level for a complete non-magic sov allowing for cheap magic resistance)
Each element increases the cost of other spellbooks by 1 point, specialising allows an extra max rank at a cost of 15, generalist allows all spellbooks to be picked up to a max of 3 without the additional costs i.e. 10, 20, 30 - 60 points total.
May not work, but I would like a bonus for:
specialising - in the first example an earth specialist would have an early shield spell with 3 extra effects at startup at a high cost (60) which would still be relevant in very late game upon learning ultra rare spells or
attack/defence specialist - cheaply gain extra strength attack spells (15) but always suffer from weaker defensive spells/magic resistance, basically cheap power has to have some costs - defence specialist could have some synergy with a mage hunter type.
generalist - the ability to cast any spell at a lower sov creation cost (capped number of ranks), while never being as strong as a specialist in early or late game it'd still give you points for other things
barbarian/witch hunter type - the ability to play without any magic bonus at all and not have a massive magic weakness (40 points for 50% resistance to all magic or whatever rank 5 gives you (it could be a free dispel magic aura or whatever), but 60 points for the same benefit if you take an offensive magic specialism as well)
Anyway the numbers aren't important... small incremental increases with caps and interacting effects can work as well as exponential costs for each rank... or a fixed number of picks to spread out... as long as in the end a fire specialist can really make a fire arrow dance as it bounces through enemy lines right from the start while a fire defence specialist can make fire armour ignite everyone nearby and give them a dessicating thirst for blood and the ability to repel arrows...
Last other thought...
Imbue champion should have a minimum level/exp/age requirement wavered in special cases (spouse, summoned hero etc) or have limited versions (imbue fire magic only) that have lesser requirements... how much do you trust your underlings? enough to give them the power to throw lightning bolts on the day you meet them?
End of tired ramblings... thoughts?