Anything I should know before diving in? I'm working on the prologues now normally getting 100 plus hit combos but I feel like I should be doing more
There are some practical breakdowns in this thread, and actually we don't really know everything right now (as is evidenced by the EXP discussion above, lol).
Some practical tips:
The flow of combat is based around trading EXP gain, Damage output, and XP gain. You can look in the stats of each pair. Check out their individual moves. Each move gains certain XP meter and does a certain class of damage. As you've already figured out, performing each different attack during the battle phase will net you a +1 attack.
Special Attacks cost 100% XP meter. You can actually earn up to 150% XP meter. Meter above 100% can be gained during Cross X (where you have assists comboing your opponent along with the primary pair). Cross X, however, does not allow the enemy to be juggled, and robs you of the ability to get Critical Hits (your pair strikes the enemy just as they're about to land from the juggle).
You should pretty much always continue to juggle enemies, even after they die. You get a higher combo for bonus XP, continue to build XP meter, and get a chance at landing criticals for bonus EXP.
Special moves do huge huge damage. You get a 20% EXP bonus for Special move finishes. Multiattacks give a 10% bonus EXP for each kill. Pairs earn multiattacks at different levels, and you won't actually see them for a long time after the prologue, until your characters are around level 19. Each successful Critical Attack earns a bonus 5% EXP. High combos and high CrossX combos also yield EXP bonuses. Special attacks can be Criticals as well. I just learned that, myself.
Tech isn't explained really well, but it's a stat that gives you a higher chance of inflicting a status effect with attacks. Those letters next to the attacks in the stat menu shows the possible status effects. I forget them right now, but they're listed earlier in the thread.
From earlier in the thread:
Stun
Poison
Bind
Down
Not at a point in the game where these are major factors in my strategy so I don't know the exact effects of each, but that's what they stand for.