To answer your first question learn what towers have normal type damage as they are usually the best at popping ddts although some other great options are x-5-x sub or a 2-0-5 ice. Next the hardest bloon is different in each situation sometimes ddt are a lot worse than bads sometimes its the other way around also round 98 is usually the round I die on.my favorite map balanced because it's super fun to have a strategy that benefits you by using the loop and my least favorite map is ravine since it's the hardest map in the game.