If you scan at 8x, the number of PI errors "should" decrease. Yes, it's a lot of information to take in at once, but with some time, you will be able to absorb it. But don't take it to heart what the scan results show, the ultimate test is whether it plays in your home player or not.
The artifacts I was referring to are some spots near the outer edges on the back (data) side. I've noticed them on the TYG02 batch I have, and once the burn/scan goes into that region, the disc can't be guaranteed to be good.
You can still find Shrink and it does have a checkbox link to burn using Nero once it finishes. I don't think the Sony firmware supports overspeeding on TYG02 (8x media), so it should only burn at 8x. As zebadee pointed out, the burst rate is not fast enough to support 16x burn and/or read speeds, but I would think that it should level off instead of dipping lower and lower, which indicates that area wasn't burned well.