Hiding stuff in barrels is OK, they won't disappear as far as I've seen.
And the "time" in the game doesn't matter, I'm already in 1887 and nothing in the game has changed.
Combining tech skills with mage skills is kinda lame, it feels like your weak in both of them. I suggest you learn the schematics for the Molotov Cocktail, Healing Salve and Fatigue Restorer, that's all you need if your playing with a mage.
A small tip: If you see ogres or skeletal Archers, switch to turn based combat ASAP. I think you know what I mean
And here's the walkthrough I'm using, it's the best I've found:
http://www.neoseeker.com/resourcelin...1023&rid=38436