Nice work on the deadlifts,dont worry about the red marks you will get used to the bar grazing you in time.At least doing the Rippetoe program gave you some experience with the major lifts which will prove useful as you transition to the single factor 5x5.You should be able to run the 5x5 longer then the rippetoe program.
Also,you mention a 110-120lb man squatting 495 for reps which I think is somewhat questionable.Was he going all the way past parallel or was he doing a piss weak quarter squat?I ask because that is a 4-4.5times bodyweight squat,which would be impressive even for a high tier powerlifter or olympic lifter,let alone your average gym patron.The world powerlifting record for a 123lb man in the squat is 644lb set by Andrzej Stanaszek which would have most likely been done in full powerlifting gear which would have helped a bit,so you can see why I am somewhat sceptical.