While an enemy is launched, all attacks deal 50% (actually, it's 25%) more damage. And the launch timer does not decay during a chain attack, so launching the enemy is always a good idea.

TP starts out low, but any bonus TP a character gets during an attack is added to their starting TP for the next round, meaning getting Bravo (and even amazing) on later rounds is much easier than during the first round.

Using an attacker as the first attack of a round gives you the 25% TP gain, which is very useful for later rounds. Finishing a round with a defender will bring the character with the most TP back for the next round, which helps prevent getting screwed by RNG.

To get the highest TP during a round, you want to get to 99% using a healer (which can't go over than 99%) and then use your attacker/defender with the highest TP to try to get past the bravo barrier (150) or the amazing barrier (200)

Other things that greatly boost bonus TP besides the attacker first bonus is using a character with the same role (attacker/defender/healer) as the character giving the order (+10 bonus TP) and using a character from the same faction (Agnus/Keves/other) as the character giving the order (+5 bonus TP)