We start with a reasonable question and get stupid answers, anyone can taxi an aircraft provided the owner is happy they have had appropriate training, as to the WX conditions, you need to be able to see enough to not hit anything.
see i.e.
Australian regulations for taxiing an aircraft; US FAA also has something called a Run-Taxi Card, I think it was related to Part 91.1(b) which states it applies to "operating" an aircraft, which definitely involves taxiing; the guy from the german maintenance organization where I had an unplanned repair showed me an officially looking endorsement card with a list of aircraft he was allowed to taxi before he moved the plane ... Unfortunatley, I don't know authorities, other than the aussies, right away with a clear document for that.
So - No, it is by no means an easy question/answer and far from stupid, either sides.