Can I still use Pentax AF 330 FTZ Flash (1991) with my digital Pentax Ist DL camera?

Some of my pictures come out TOO BRIGHT

no, you will need to use a digitally compatible flash such as the AF-360FGZ Electronic Flash.

i am sure u cannot, it will cause ur camera unstable u might lose some file or picture. the speed of your old one is slow while now camera able to take 3 frame per sec tt fast man