Not necessarily.
The best course of action to get both trophies in one playthrough quickly and with the least amount of pain is to do the following:
- Start a beginner mode playthrough
- Select Pro codes
- Turn all of the Pro codes on for each of the battles that require them (only select mini and main bosses contribute to the Pro Rank, which you can see from the Pro codes menu). I turned default stats off and turned formchanges on when I got to the first boss fight of the Keyblade Graveyard because I was getting sick of the game by this point.
- Level up to 99.
- Turn off some of the Pro codes when you get to Limit Cut, to make those fights easier. I had default stats turned off, I let myself use battle items, I let myself use formchanges. This should get you 15,000 points per battle except for Luxord, since he's a gimmick fight and you can have more codes turned on for the full 25,000.
- For me, I unlocked the Risk Taker trophy after beating all thirteen bosses. Some get it earlier because they kept all pro codes on during the Keyblade Graveyard onwards.
- Turn all Pro codes off and beat the Secret Boss.
- This unlocks EZ codes and you can load up the main game and complete those merits.
You can do EZ modes on their own playthrough, but unlocking Pro codes mean that you'd need to be extremely skilled at defeating the 14 super bosses (and Dark Inferno) with every single Pro code on.
As for the EZ code merits:
- Defeat 13 enemies in the air without landing! Enemies defeat with magic, links, team commands, or attractions are not counted - easy enough to do. Apparently shotlocks count.
- Defeat 20 Shadows/Neoshadows at one time using Rage Form. - Turn on the EZ code to get rage form easier and find a battle portal with a lot of these Heartless, like Battle Portal 0
- Use any link to defeat 77 enemies at one time! - I've heard that the Montropolis Flan with Simba and one hit KO is the best for this post-game. I did this and the one above in Olympus during the Lich fight.
- Freeze and shatter 30 enemies in one battle! - Toy Box battle portal where the world's boss was. If you're killing them too fast, try and use Blizzard instead. You need to freeze the Heartless and THEN the next attack needs to kill them. With MP regen on, you can just spam blizzard to do this.
- Use any attraction to defeat 5 Gigas toys at one time! - Best spot imo is up the top of Toy Box, in the playground area. Turn on the EZ code for more attractions and one hit KO and splash mountain them.
- Travel from the tower in the forest to the Kingdom of Corona without walking on the ground, and landing only up to 5 times! - Not as bad as it sounds, just be careful after running up walls that you don't accidentally walk when you reach the top.
- Clear the Schwarzgeist in Misty Stream with an A rank! - turn the Gummi Ship EZ code on, choose the gold highwind and just defeat the shields for 10,000 points until you hit A rank, then defeat the boss.
- Defeat 10 enemies at one time using the team attack Scream Strike. - turn on the 0 AP EZ code, turn the team attack at the start of battle ability for Mike and Sulley to on, and just find a spot. I got mine in the area where you fight a bunch of Heartless while the walls were electrocuted.
- Clear a difficulty ★★✰ Battlegate while only having the code “Survival” ON. - self explanatory, I got mine in the Toy Box battle portal on the ground floor.