Use "Je suis prince" if that is his actual occupation. If he's just being glib about being one heck of a nice guy, then you can stick the "un" in there.
I have never heard this pronunciation of "oui" before Duolingo. Is it actually pronounced like this anywhere in the world?
it seems pretty normal to me--basically how my French teacher at school pronounces it, and she has been to France and Quebec. How else have you heard it pronounced?
Maybe he's talking about the male voice-over. The female VO says it as "we" instead of "oowyi".
And that's how you normally pronounce "oui", as one syllable. Here, for some reason, the E sound is a bit longer, as if he were letting out a doubtful "oui". Maybe, he's not sure or is just lying about being a prince!
Why use un now? I thought u dont use any article when talk about your proffesion