i think rangers + mage slow and fireballs are a good counter to ogres, as long as blizzard/D&D is nerfed to have range 5 and mana cost to like 75
problem with the strongest spells is that they are so powerful in comparison to anything else.
there're way more area of effect attacks/spells that could help out against bloodlust, without necessarily removing the insane damage that bloodlust does.
One of the other problems is that present in multiplayer, its the fact people tend to play on the fastest speed in war2, which makes impossible to micro with spells and units like rangers. Including the overall big latency. To anybody outside of russia or USA.
Skeletons definetely deserve something like 60 HP, more attack speed, a bit of armor and more damage, like on my mods. If skeletons are present in play, you will automatically see exorcism being used way more.
Flame shield is the other so undervalued and non used spell in game, which i think could be way more fun to see in action, if blizzard/D&D is nerfed in range and mana cost.
Death and decay and blizzard may indeed need some rework and rebalance , I stated before that teching into rangers is quite a task and I doubt someone would consider starting ranger spam until they get +2 dmg rangers also share the same building with paladins which u would need to protect the other units so the humans are put in this difficult situation where they have to get multiple barracks and train a multitude of units and pay a huge amount of resources to upgrade them while orc is just "bloodlust go brrrrrr" with some DKs as such its better to simply nerf bloodlust while I get that it would take some of the awesomeness the spell has x1.5 will be a middle ground I believe , interesting stuff about skeletons they are awful not worth the effort , and flame shield is really a cool spell it could force the enemy to micro their units carefully isolating that unit from the rest problem is its double edged sword I think the lightning shield from wc3 has way more impact due to how the game plays like in wc2 it more or less spammy game but in 3 forcing the enemy to relocate a unit could make it easier to kill and secure a tactical victory for the player.
On the topic of speed it really do seem to play a role personally I can't stand the stupidity of units running around like some sort of racing car and the running animations are way too goofy on fastest speed a possible solution would be to rework the start of the game instead of starting with a single worker u start with a townhall instead as I heard that the reason fastest speed is played is due to the very slow start of the game.