I'm using rubyripper to rip my CDs with a good Lite-On drive. I'm having rubyripper re-read 5 times to do it's best to verify that it's read is correct since I'm not using AR. My CDs range from perfect to only slightly scratched. Is 5 passes overkill?

IMO one pass should do it. That's all I ever do unless I get a glitch in a file and will then try it again but in the DVD writer instead. Nearly always the anomaly happens at the same sample number so I deduce it's a flaw in the original that got past QC. If it were on my disc, I would expect the 2 drives to give different results. Of course if you have nothing else to do there is no harm in ripping 5 times outside of wearing out the drive 5 times faster.

G²

There are those here at HA who will tell you that repeated reads of the same sector will not guarantee that the rip is free of errors, as "consistent" errors are demonstrable and real.

Technology being what it is, the default 2 passes constitutes the basic "Test and Copy" that comprises the core of Exact Audio Copy's ripping tech, minus the error correction.