Is médico also correct for 'doctor'? Are there different contexts, or are médico and doutor interchangeable?
Médico and Doutor are used the same way related to the Healthy System. But if a person gets his Master degree /PhD in some area, he is also a Doutor, but not médico. Doutor has a wider usage, for anybody who is specialized in something, as a lawyer, biologist, etc. So, a médico is also a doutor, but a doutor isn't necessarily a médico.
In my language, we also have a word for "doctor" and a word for "physician," but in quotidian language, we almost always say "doctor" and not "physician." Is médico more formal in Brazilian Portuguese as well?
You all are doctors should be accepted too. Yes, saying, "You are doctors." does imply the plural you, but I like to translate the plural you as you all to commit it to memory, as well as it being commonly heard, just like you guys/y'all.
I get really fed up with saying it perfectly OK, but the speech recognition taking so long that it decides I had it wrong - and there is no button to say 'let me say it again until the computer/tablet/phone picks it up'. No way of reporting this fault either. On my ipad it does give me time to do it again if only part of the sentence registers.