I really have no idea what to look forward to with this game but I've heard some really good things from the alpha/beta
About classes and stuff. I want to have 2 physical fighters coz I don't play that magic shit. Thing is the environmental stuff sounds so good I feel like I'd be gimping myself. What class would go well with a warrior?
Anything. You can do the environmental stuff without magic (candles to set off fires, water barrels to dowse flames, oil barrels to prime fries, etc..., and one time use scrolls), but magic definitely makes it easier to get the most out of the system.
As one of the 2 companions is a mage, if you want both you'll get the chance to explore the potential even if you don't want to. The other companion is a Warrior, so again if you want both this might affect your character set up choices at the start.
Not sure what henchmen we'll be getting (party members with no story elements), but if you want the story based party members it might change how you're planning to start.