I'm not even sure how you managed running painter 8 on a intel mac - painter IX only worked for me after installing painter IX.5 update that added rosetta compatibility to run a power-pc native application.
I remember Fredbt had troubles running painter 7 on mac os x, so I think it's just your version being too old, or not playing fine with today's wacom drivers.
I suggest downloading painter 12 trial version and checking if it works finely.
You won't be eligible for upgrade pricing for 12, but at least you can get a feel for this update and see if you need it;
there's also an option to install sheepshaver and set up a virtual machine with mac os 9, and install your intuos 2 drivers and painter 8 there, but I'm not sure if speed/stability are sufficient enough.
on the fourth day of glitchmas my painter™ gave to me
four random crashes, three broken brushes, two system hangups & one corrupted workspace