Of course: mochiron, touzen, machigainai (もちろん、当然、間違いない） souda (as in そうです) = I agree souka (as in そうですか) = Is that true? Really? I didn't know that! (also doubtfully: Really...? Dunno if I agree...) yappari ne (as in やっぱりそうですね) = That's totally true, isn't it! I agree! (more formal: yahari やはり)

もちろん。を、おおくつかいます。

People always use "touzen"and"a tarimae".；）

Completely depends on the context :) Touzen is more like, "no doubt"(like its already decided) and mochiron is more, "yeah, that is of course true but this blabla. . ." I think you will learn the styles the more Japanese you study ^_^