6)I guess they're still helpful, only the clicked one gives you 150% bonus for 20 minutes or so. At least that's what the game says.
7)This was a no-brainer... For same intensity drills, yes. But if you compare pass go shoot L2 with fast counterattack L1, then no. But a pass go shoot L2 is better than stretching L1 or pass go shoot L1. But there seems to be no difference between very easy drills L1 and L2. I have warm up L2 but still +1 per each player.