Re. the discussion as to whether the eight-engine solution was or was not chosen because of the engine-out case - I believe that it certainly was a factor. But a lot of people overlook another issue: there are three candidate engines for an eight-engine layout, but since the last time re-engining was studied, the two engines that would work for a four-engine B-52 (RB211-535 and PW2000) have ceased production.
LO,
Back in 2005 we discussed this often amongst the crew dogs. The original proposal was for 4 RB211-535's, engine out had them looking at other options like CFM-56's on the outboard pods, but two engine types on the same airframe doesn't help the cost argument. Ultimately, the final nail in the coffin for the 4 engine proposals was low oil prices in the late 90's early 2000's and all of the spare TF-33's taken from C-141's and KC-135E's. They could mod the tail and rudder to address the engine out, but that also cut against the cost savings argument. Your points for today's proposal are spot on, the other thing I suspect is they've finally worked their way through the inventory of C-141/KC-135E spares.
FWIW, Boeing Wichita has a model of the 4 engine BUFF hanging from the ceiling down in the B-52 area, we saw it every time we went there.