It's not 'musieć' (must, have to), it's 'móc' (may, be able to, sometimes 'can'). Just for the record, the declension is here.
The more polite version, corresponding to 'could you', uses conditional. A quick look in the declension table, and we arrive at "Czy mógłbyś przynieść chleb i wino?" :)
And then of course there's plural 'you', so respectively 'możecie' and 'moglibyście'/'mogłybyście' (first one for masculine personal, the other for not masculine-personal).
Given how this website works and what method it uses, sometimes we have to be very strict in terms of grammar to make sure our learners know exactly what is what. Obviously if you were translating some real Polish text and translated it the way you mentioned that would indeed be a natural translation.
No, I'm Polish and I've spent my entire life here. My English is pretty good, I believe, but it's definitely not native-like. We have natives helping us decide in some cases, so unless the answer is totally obvious, usually my comment is written after a consultation.
Actually now we very often do accept "some". English seems to use it a lot more often than Polish uses "trochę". Some things simply change with time and things about our policy that I wrote months ago may not be true anymore.
So as for your longest comment: yeah, now we do not have anything against "some" anymore. "any" is also usually accepted if it makes sense on its own in English. It's just that our database is quite big and not every sentence has been edited yet. Added "some" here.
Thank you for your reply, dziękuje. Honestly, I have no idea how Duolingo works inside. When I lose virtual hearts in the app in such cases as I've described, it almost hurts. I hope the more people drill through the course and provide their feedback, the more of fun it can become, provided there is also a technical team on the other side to make it perfect.