What does the blue meter do? I see it changes depending on how much you win by, but does, say, the difference between the red/blue meters matter? I can't tell if it matters if I keep my pokemon alive.
Do you mean the one that gets filled after the battle ends? Pretty sure it's how much exp you get from the battle. Also, you get a X2 bonus if you wipe the other team AND/OR if none of your mons faints. If you do both on the same battle, you get a X4 exp bonus, which is really helpful in the late game.
I tested this using the same team against Youngster Joey, and I think you're right. Started with Doublade and Gogoat, the first time I won with only a Flawless Victory. I reset, picked the same team, and this time I won with both Flawless Victory and a Wipeout. And in both my exp after the battle looks exactly the same.