Not that fast. I can activate mine with a weak shot that barely hits the second gate and rolls back down to the bottom flippers. I’d adjust the switches, though yours would only reward shots that fully lift the top gate, which is also a valid configuration, so long as every “made” shot registers.

I have a set, I needed a replacement for my left ball guide. They seem really nice to me but what specifically are you looking for?

I certainly didn't notice anything like that, I'll have another look and post a pic here for you.

Good news! The plastics seem to be very good matches with the originals.

Here's a pic with the left-ball-guide being new plastic and the rest stock:
IMG_5601 (resized).JPG

And here's a picture after I also changed out the scratched left sling plastic for the new replacement.
IMG_5603 (resized).JPG

Based on the photo the new plastics might be a hair brighter/more transparent than the originals (and also seem to be slightly higher definition/less blurry) but by eye-sight alone you wouldn't detect a difference.