Friend stephenbal4: Though I’m not fluent in Russian and you didn’t ask for it, because I’m such a nice guy (and if you doubt it, ask me and I’ll confirm it!), here’s a rule that I think I once saw, somewhere, sometime ago on the subject you asked about. When you encounter letter combinations of “его” or “ого”, AND the letter preceding the letter”г” (that is, the “е” or the “о”) is NOT accented/stressed, then the “г” is pronounced like a “в”. Other than those times, the letter “г” is pronounced like a “г”. That is my recollection. And I’d sure like to hear from someone fluent in the tongue, to learn whether it is correct.
Yes. But 'what is your doctor called?' is perfectly ok, and was marked wrong. I've reported it. However, I wouldn't use it to someone's face (what are you called) but only in the first and third persons, he's called, I'm called, they're called. To someone's face - in the second person - you'd normally ask, 'what's your name', although 'what are you called' would not be gramatically wrong, just foreign-sounding.
Зовут is actually a verb: it is the third person plural conjugation of звать, which is an infinitive meaning "to call." In constructions such as "Как зовут xyz?," where xyz is replaced by a direct object/accusative (тебя, вас, меня, твою собаку, вашего врача, etc.), it means literally, "How do they call xyz?" How do they call you? How do they call me? How do they call your dog? How do they call your doctor? (Only note that this construction leaves out the word "они" - it is not, "Как они зовут тебя?" This implies, to me, less of a "pro-drop" formation which is constantly argued about on Duolingo and more instead an idiomatic phrase.) In any event, in English, we would more naturally phrase this, "What is your name / my name / your dog's name / your doctor's name?"
Имя, on the other hand, is a noun for the word "name" - more specifically, a person's first name. Ваше имя - Oliver. Моё имя - Ruth. Note from my use of ваше and моё that it is an irregular noun; usually nouns ending in я are feminine, but this noun happens to be neuter.
(Original reply edited because of some rather unexpected formatting results.)