updating older PT LE on older Mac

[skfdude]

Have PT LE V 7.3.1 installed on iMac 24" OS X V 10.4.11. Have the 003 console plugged into the Mac and all seems to be working. Going to begin to learn to use PT so pretty much a newbie. A few questions:
1) I've been told if you update the Mac OS to more current OS it can prevent PT from operating. Would I need to or/can I update the PT LE as well to make it work with upgraded Mac OS. Thoughts/comments on this?
2) If I need expert guidance to get all flowing well from a software/IT perspective can Avid support provide this for me if I pay for some level of support? If so what is best place to start for this support? I'm the original owner of the Mac and PT LE 003 (both purchased new in mid 2007), just sidetracked in life for a few years but diving back in. Thanks!