my guess is that you have an older video card that doesn't support pixel shader 2.0 depending on your graphics card type I would recommend the following nvidia cards pete's d3d dx6 plugin or ati cards the one you have it should run set to nice if you experience lag take the vram off auto and set it to it's maximum also make sure you have special game fixes on and the one checked for FF9
as for sound I either use the default or eternal spu.
the reason many people suggest 1.5.2 for FF9 or just multi disk games in general is the disk swapping in 1.7.0 is broken but that can be fixed by mounting the game with a virtual drive like daemon tools lite and playing via run cd.
link to daemon tools
http://www.daemon-tools.cc/eng/products/dtLite