about your freezes, hmm, dont know for sure
but it sounds like those points are when a cd track starts to play. If you don't need it you can try disable CDDA sound.
Or you might try another CDROM plugin, like Pete's.
i tell you tho, for me GT1 in ePSXe has all the tracks screwed up. for example at the end of a race the music is supposed to change to a certain track, but epsxe will play the wrong one.