I do agree that - 50 % is to much and not what i intended.
Unit with -50 % blitz will benefit only from the ability to split dmg BUT at the cost of loosing half his power when moved.
Suggested -25/33 should do just fine.
As for the artillery i only wanted to avoid range 4 land units as they r devastating vs AI.
I did NOT ask to remove range promotion. Artillery would simply get it for free - so it would start with range of 2 like cannon , but with free range making it 3.
I agree with your first two point: a 150% damage blitz getting double XP seems fair for an expensive promotion.
But by your logic in the last sentence we should remove all aircraft too since their range is much larger than 4 tiles. I've never seen a situation where range four artillery helped me win a war I wasn't already running away with due to a tech lead.