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.
Honestly if you're carrying a barrel of that size full of liquid you should be unable to jump, hold weapons, use items ect as well. It should be like when Link from Zelda picks up a rock over his head. Until you throw the rock you can't do much else.
