Seriously, it's scripted poorly.
But this Raven's fault, not the Kmod team's.

For example I come from tunnel and just before the entrance and I shoot with bloodscourge (mage weapon 4) and the fireballs explode in front of my face instead of going towards enemy.

And in places like one of the sub level in the Heresiarch's seminary, the one where you begin in a place where is lots of boxes and it's a maze.
Well there you can't even fire well with bloodscourge.
Since the fireballs won't even fly.

And there is no wall in front of me to stop them, mind you.

I just wanted to ask does something like this happen to you ?

Also, are you considering any weapon scripting changes in CE ??

This is a thing of the DOOM engine itself and concerns weapons from the Plasma Gun and the Rocket Launcher through the Hellstaff and the Crossbow to the Firestorm and the Bloodscourge. If it makes you feel any better, similar probs exist in later games (Quake and even Unreal engine based ones).

As for SE, accent will be a lot more on melee weapons and spells, fantasy versions of the machine gun and the BFG will be less important than in Hexen (which was already a significant improvement over Heretic in this). BTW you shouldn't complain about the Bloodscourge until you tried to fire the Arc of Death in any close spaces...

Worse yet, if the Arc of Death hits an enemy near a wall, there's a fairly good chance that the wall will cancel out the attack before it does much damage.