I hate to do this, but the business side of me me must pick your Utopian post apart. You simply have no clue how the real world works:
****Pain Of Salvation are already popular enough to do a two-leg European tour, it's not like they're some uber-underground band.
You do realize that they are lucky to play in front of 150 people on that European tour each night right? They wouldn't draw that many in any city here in the States other than the larger places like NYC, Chicago, etc. The real world is not a core group of forums where they are known.
****And yes, I think 20 minutes is ridiculous. It takes at least that, if not more like thirty just to get the band's equipment set up, so why not give them a longer set so they can actually play more than a few songs?
In a true traveling festival set-up, it does not take that long because you aren't given that long. There is a very tight schedule to keep. This is not Ozzfest where you can start at 11am. The economics simply don't justify it.
***And if that would mean making the lineup smaller, then do that.
No, do not. If you are going to do that, then turn it back into a venue tour. The fact is that the big bands are the draw and the smaller bands are brought into appeal to the fringe element in that they have a draw to another segment that may not see the tour otherwise.
***There are only three bands on that second-stage "maybes" list that are even deserving of being on a tour like this, so if Dave Mustaine is concerned about quality, he'll let the lineup reflect that.
This is horseshit. There isn't a single tour booked in the States based on "artistic integerity." Besides, this type of booking is meant to be very diverse and appeal to a broad audience. The mallrats are going to come for Fear Factory and DEP, not DT. Their dollar counts just the same.
****Or, Dave Mustaine will just be an asshole and put a bunch of pop bands on the bill so he can fill his pocket as much as possible, while saying he's keeping musical integrity by having Dream Theater on the main stage.