regarding steam

[Recolector]

Could i buy this game from steam then switch to the official launcher? or I would be stuck with steam?

[Urthdigger]

It's the same launcher. Only thing to note is if you buy it on Steam you must buy the expansions through Steam as well.

[worldofneil]

Adding what Urthdigger wrote, it's the key you get given and use to activate the game that determines if you have a Steam account or not. You can't change from Steam to non-Steam and vice versa.

[AskaRay]

I use the game launcher and not Steam. Just open the game folder, and like others have said you have to buy the expansion through steam too.