Yes, Salvage should be reduced as well if you're able to solo that. I haven't done Salvage in so long since it was 75 cap, so I don't know how easy it is nowadays.
As for the lamps, I think the least amount of lights is 3 and it goes 3-6, but I suppose that's because the minimum to enter is 3 people. Maybe if only one person enters then there might only be one light? Even if it's a specific order for two lights, then that person soloing can run from the first light and hit that then run to the second light and hit that. For hitting the lights at the same time though there would have to be only one light if you're going in solo otherwise you would be stuck on that floor forever unless the lights are all close to one another.
