I've posted this already on another thread of very similar situation, but here it is for those who don't wanna look
Hello gentleman, I've just registered to be able to share my solution with you all for this old but gold game.
I'm currently running it on the latest version of PCSX2 (it is fairly better than when I used to play some of the ps2 games on the emulator)
First of all: the issue of the memory card freeze.
I've managed to solve it by unplugging and plugging back the memory cards and playing around with them MEANWHILE the game was working. Once you get your memory cards to work as you need to make sure to keep always a save state from where to continue on, since that way you won't have to repeat that process.
Secondly, the issue of the freezes after battles (the mission complete freeze).
I've come around a fairly reliable solution (note, you'll still need a few tries, but saving the state slightly before you're ending a battle requires you at most 10-20 seconds to reach the same point again)
Here's the hacks you need to activate first:
1- Disable all of the speedhacks (the game should be smooth already even without the need of hacks)
1.1- This is not necessary, but some ppl have had issues with graphic bugs etc and in my case I only had 1 occurance hence I suggest to use x3 native.
2- Make sure to enable: EE timing hack, skip MPEG hack, OPH flag hack, ignore DMAC, "Switch to GSdx software rendering when a FMV plays".
Now, those things should generally work by themselves, but It happened sometimes that my game would freeze anyway. What I'd do is save state slightly before finishing a battle and in the case the freeze happens, simply rewind to your latest save slot and retry by doing even just 1 thing differently (instead of attacking, def then attack or mov then atk etc). Sometimes it works even without having to do something particularly different, but ironically it seemed to "change" the outcome.
This solution is by far not 100% reliable, but it managed to help me move on from this bug on a fairly good reliable speed.
Lastly, for those who've the freeze at boot: simply smash your X and skip that cursed vid.
I wish you all fun and enjoy this awesome game