Great thread BJJ!
1) I've had one perfect UFC event, UFC on FUEL 4. I went 11-0. It felt good, but kind of shitty at the same time because my rank for the event was #363!!! So I'm guessing either a lot of people also went 11-0 and or a lot of people did significantly better picking finishes. And while I don't know if we are counting secondary league, I have 2 perfects there. 10-0 on the Rockhold-Jardine combo card (93 pts... 4th place! Heartbreakingly close to top score) and 7-0 on the Bellator 68 combo card.
As for whether it's luck or skill, I'd say it has to be a combination of both. The fights need to play out almost exactly as you see them in your head to get that perfect event. As we know, the unforeseen happens quite often in MMA, in and out of the cage!
2) I was the victim of a stupid pick a couple of times. UFC 126 I went 10-1, missing only the main event... Forrest Griffin vs. Rich Franklin. I picked Franklin, and Griffin won a UD. I feel stupid about that one because I went to look at that card and see which fight I missed, and I could have sworn I had Griffin in that fight....
UFC 131 I went 11-1, missing the Nick Ring - James Head fight by picking Head. I think I just picked him based on his win over Gerald Harris, which I hadn't even seen
UFC 133 I went 10-1. I picked Paul Bradley over Rafael Natal. I couldn't even tell you who the hell Paul Bradley is... probably a TUF alumni. I don't think I had seen Natal fight at that point. Natal is another Stefan Struve for me, I pick him and he loses, pick against him and he wins.
Edit: I'm with Rabi. Although FUEL 4 is my only card to get all winners, I was ranked higher in literally every other event I mentioned in this post. I've never gotten higher than in the 40's in points for an individual UFC. I had a couple top 15's in L2.