- Most of the spells should be available through the spellbooks including most summons
- The path of the mage tree should improve spells with higher effect, lower mana cost and lower casting time
- The path of the mage tree should increase the attack, defense, ... of summons by 50 %
but that's pretty much what they are doing now?! you have that whole line of traits that increases the effect, and the other line that increases the level (i.e. attack, defense, HP...) of summons (not by 50% but more gradually). not sure why you want to unlock summons with the general spell traits. i mean, they specifically changed that portion of the spell trees from FE to LH. apparently, the devs don't want "Hank the Tank" to be able to waste 100 mana to summon a weak ass level 1 earth elemental - they want summoning to be a mage thing, and more specifically a specialization. summons are decent now since you have to pick up some extra levels and have to unlock them specifically. that's a better mechanic IMO, since it protects AI and unexperienced players from wasting resources on low strength summons.
the staff suggestion makes sense, though. a low tier traits could do that so you could still do some damage with your mage when you don't have enough mana to cast spells (or don't want to waste mana for easier fights)
also, i agree with the magic tech tree unlocking some mage gear. would be nice if you could actually buy adept/mage robes (the robes with spell cost discount and some spell mastery) and maybe also stuff like the healer ring and the fire damage ring (at a relatively high tech level)