While item 1 looks like a good idea it would require a comprehensive combat redesign. Think of the binary effects such as shield bash or blunt knock-down: how would they be implemented in this system? These combat effects which are hit or miss cannot be adapted to a partial hit from a group. Hence a redesign would be needed to maintain some semblance to the current system.
Ongr the unbound is tameable with the ascian collar. By himself he is very formidable - but he is upgradable to a group. In my current game he has 420 attack and 384 hitpoints after upgrading to a group of four. Not intended? The only downside to taming him is that he never gains experience from combat. He might gain xp from quests but haven't finished any with him in the army yet.
Hysteresis.
Now he appears in a goody hut.
Initiative would likely take a big hit if staves were all made to be ranged - which would still leave daggers a better choice for casters. Perhaps a few options on staves such as lower mana cost or slight damage boost would make them useful.
I agree that there are too many heroes force fed to players. The experience system dictates only one hero per stack, and early game it is all I can muster to fill out one army stack (led by the sovereign). Meanwhile there are 3 or 4 useless heroes costing money and gaining no xp. I'd much rather choose a higher level champion at a time when the kingdom can support a second army.
Having to go deep into the trees now compared to the randomness in FE also affects the available skills. Shield wall is now a very hard perk to attain (one of the best in defender line imo) where in FE it was often available early. It takes a lot of fighting to get that deep into a tree - by the time you get a hero to that point you are most likely stomping on dragons anyway.
Archery suffers indirectly because of the new swarm mechanic for melee. Melee is now more powerful but archery stays the same. Archery needs something to fill a niche. More damage, special attacks or something is needed.
The way that mounts work as a resource and upgrade seems lacking to me. As a resource - other resources remain important for the entire game. Crystal and metal are critical components in unit upgrades and unit production. Mounts on the other hand are abundant. Producing a mounted unit takes only a few mounts and will never need more for an upgrade. I always end up with hundreds and hundreds of wargs and horses with nowhere to use them. Another side effect is that there is no reason to
I've played the mod for a few games and like a lot of the changes. I do have a few suggestions. I think lair monsters scale up in difficulty way too fast even at the lower world difficulty settings. AI players can not cope and simply get hemmed in and are unable to expand. I can usually manage to get 3 cities settled before the monster spawn scales out of control, and then it is a matter of waiting on research to catch up before venturing out to kill the spawn and lairs.