Regarding the onstage antics. I saw Maiden here in Dallas in 1999 at the long defunct Bronco Bowl. Virtual XI was the latest studio album and I think they were touring for the Ed Hunter game which may have not even been released at that point. I went into that show clueless with some friends who simply wanted to see "Iron Maiden". No one know who was in the band. Hell, I still thought Blaze was still their singer and was still pretty casual in my fandom myself.
So you can imagine my surprise when Maiden took the stage and there was Bruce fronting the band! I was completely shocked and had no clue that he had rejoined. What a cool way to find out that Bruce was back! Plus they had three guitarists. This also perplexed me. I thought Maiden only had two guitarists? As a casual Maiden fan, I did not know the guitarists names or who did what. I did notice that one guitarist spent like 70% of the show spinning his guitar around his head (probably exaggerating the way memory cheats). But the music and performance was awesome. They played almost all of the Ed Hunter greatest hits package so the set was killer. This performance left a big impact on my friends who loved all the rock'n'roll spectacle stuff. They absolutely loved Janick spinning his guitar! Well the same group of us went to see Maiden again in 2010 for the TFF tour hoping to relive the experience, and as you could guess everyone in our group pretty much hated the show. Probably mostly due to the set list of newer material. But I remember the distinct disappointment from my friends (again these are casual music listeners) that "the guitarist" wasn't spinning his guitar enough
(like he was at that impressionable performance 10 years earlier). Our comedy quote of that evening: "They no longer gallop. They only march."
I've been trying to understand all this in hindsight. My guess is when Adrian came back that immediately plugged a hole freeing Janick up to do whatever he pleases on stage (so he was basically a 5th wheel for much of that '99 show of mostly older pre-90s material). However, as time went by, Maiden had more of a chance to work together and to really integrate the 3 guitar thing to all their past songs. Maybe on the Ed Hunter tour the merger was too fresh, so depending on the song one of the guitarists was surplus to requirements. I've also had a chance to go back and review that 2010 setlist to try to understand why it was so lacking in up tempo numbers. Let's just say you have to be a big fan of BNW, DoD and AMoLaD to like that setlist.
Anyhow, guitar dancing aside, the pyrotechnics will always get the biggest applause at any live shows..be it Kiss, Rush, etc... It's probably part of our monkey DNA.