I disagree that flaming people is fine if they're using an "abuse strat." When I'm fencing, I don't scream at my opponent during the bout even if they're doing something obnoxious... and I would expect similar conduct in any other sport. Now, if you wanna discuss it with them after the match, that's another thing. But screaming at someone during competition itself is never okay in any sport, e or otherwise, in my book.
I consider both things bad sportmanship. With the little difference that one is just a player/customer and the other one is a developer.
I expect a developer to not troll, abuse or make fun of a player.
If he wants to test new strats for balance's sake I was thought that they have a beta server to try these things.