I use Shuguang Psvance gold base tube and set bias at 5mv, the tubes has been quite stable. I have used these tubes for almost one year now and find it very stable. It all depends what brand you use. My friend has Reference One with EH tubes. He had replaced only one tube after 6 years and another one or two for another two years. I know EH tubes are very stable and reliable, sonically is not my prefer brand. I had used reissued Western Electric in the 90s, they are pricy and stable.
Know nothing about the Hansen speaker, so can't say any more.
With pure Class A at 80W, I am sure it can drive most speakers. Again it depends very much on the room size and type of music you listen.
I think the biggest improvement in Ref 2 lies on the power with ease of control at lower end. Better extension and lesser coloration than Ref 1. It is estimated at least 20% bigger and heavier that Ref 1. Some people love 300B sound because of the mid range magic, the finesse and delicacy in highs. You won't find its fullness in the mid in Ref 2, and still has the highs like Ref One.