There are certain areas where there are way too many barrels.
In the temple by the priestess, there are three NPCs guarding a locked room full of crates and chests with stuff and lots of barrels of wine, gunpowder etc.
One of the enemies shoots a fire arrow at me, exploding a barrel next to me, which makes other barrels explode, which makes other barrels explode and it spills out of the room until a quarter of the main chamber is on fire!
3/4 of my party die, the three enemies die, because they were standing right in the middle of all those barrels, and all of the crates, chests and loot are destroyed.
Great job NPC!
As for taking barrels with you and using them, they should probably be heavier so the amount of barrels you can take with you would be severely limited.
A party of 4 people should not be able to carry 5 barrels.
