Heroes 5.5 WarGame Edition - Tactical Edition.

Logistics: I wish we could remove it altogether and instead give all heroes speed and pathfinding (built-in). And let logistics itself increase the initiative of units in battle, like attack.

Then we would have commanders who have taken luck, attack, leadership, and logistics, with an army that will move several times in a row before each enemy unit. What's the point of creating another skill branch to increase initiative when leadership already exists?

Knowing different schools of magic already gives you a lot. Spells now have a strength dependency on your level of knowledge of the school itself. So, it's always beneficial to take it. And the fact that you prefer to always use Blind instead of other spells is already your own choice. Darkness won't help you at all against an enemy spellcaster, so its versatility is questionable. You can deal with commanders by maneuvering through the terrain.

With Summoning, and with a favorable arrangement of objects and soldiers on the map, you can block everything you need from large enemy units. So, Summoning does its job perfectly. It's especially convenient for patching up holes when defending fortresses. And if you manage to break through with a catapult, that's even better.
Chaos works great as a counter to enemy formations. One Fireball, and a hero of the Order faction will already start to wonder whether it's worth making a formation or whether it's better to scatter the soldiers. Although, I'm not sure about destroying single targets.

Divine Intervention is a great thing if you have a lot of units. Oh, how awesome it is to use it, being a Demon or Necromancer. You can not only waste a weak tier of units, but also put it in a position where it will be destroyed along with itself by enemy attacks. The mere presence of this ability on a hero forces the opponent to seriously reconsider priorities and possibly postpone finishing off your group of peasants for a couple of rounds. And in that time, you can do a lot with them.

Berserk in its current form is ideal. You cast it on an enemy archer, and you're a genius. The archer runs into a bad position, takes a retaliatory attack, and gets hit hard. It's a great thing. And if you add complex conditions for choosing targets, it will either become too strong due to effectively sacrificing enemy groups on themselves, or it will become completely uncontrollable, and then you will start to think "Is it even necessary?", you disable an enemy squad, and then it finds a good moment and destroys your squad, because it calculated how to inflict the most damage in that turn