Generally speaking, is 50 degrees latitude high latitude already?
Latitude goes from zero to 90. So if you are going to divided it into HIGH and LOW latitude then 45 degrees would be the dividing point. So yes, 50 degrees is high.
normally qualifies as mid-latitude. Why? because it is about in the middle of 0 to 90. 0-30=low, 30-60=middle, 60-90=high. Just a number thing.
Yes, specifically rather than generally. But not "very high".
Not really. 50° North is roughly the latitude of the English Channel. North of Latitude 60° is where you'd start seeing polar environment. The Arctic circle is latitude 66°33′47.5″