A) While I do more warm-water fishing than trout fishing, I do a fair amount of both.
B) I do more fishing in moving waters, but, again, I do a fair amount of both.
C) Stillwater fishing is far easier, IMO. (Not necessarily more productive, just easier.)
D) I prefer stream fishing, generally, but there are exceptions. To me, stream fishing is more technical, and presents more of a challenge. That's why I prefer it.