I agree that the verb "to get" is vastly misused in the English language and your two examples illustrate that. However, "Have you got a new car?" tends to be correct English usage whereas "Do you have a new car?" tends to be trans-Atlantic usage. I don't know if the computer model will allow it but, when used correctly, I think it should be accepted.
If you are saying it is a valid translation then I agree. If you are saying it should be accepted on Duolingo then maybe not. They use translations that help you learn Gaelic without getting confused. Got is translated differently when you say she got a new car or he got sent off so it is best avoided on this course in this situation.
Yes. In all European languages I know, apart from English and Welsh (and maybe here sister languages?), that have either, they are pretty confused. Latin v was originally /w/ and changed later. German w is /v/ in the standard dialect but not all dialects. Foreigners often get them confused in English. They are so interchangeable that you should generally regard them as different ways to pronounce the same phoneme. In both Gaelic and Irish it varies with dialect, broad/slender, bh/mh, position in word etc. and sometimes there is just no obvious logic. So understand both and say whatever comes naturally after doing this course, but don't worry about it, as people will still understand you, even if they wonder where your accent is from. D