So I followed the instructions in reply #5, but it wouldn't let me perform the first of the two commands, since this is not a virtual machine. However, I ran the second of the two, turned the rootless back on, rebooted, and then it allowed the install to go forward. I'm waiting for it to finish, so not sure how well CS5 will perform once install is complete, but I am optimistic. I'll post the results here after I test it.
Update: Illustrator seems to work, except that I am having the same issue with the whole thing crashing when trying to use the eyedropper tool, as mentioned in another comment. Rather annoying, but I can probably work around it if I have to. Anyone else found a fix for that?
Stop! Just install the Java 6 runtime mentioned in the post above - supplied by Apple. NO NEED to go through all this terminal hacking!
https://support.apple.com/kb/DL1824?viewlocale=en_US&locale=en_US