Rear seats and doors are definitely different.
Rear doors I get. ~2" longer wheelbase on the wagon and different shaped doors.
I think you're correct on all 5 counts. For #2, the S60R rear seat is more "buckety" on the outboard positions but in the V70R it's less so - more of a proper three-across bench seat.To the OP, from the B-pillar forward, S60 and V70 would be the same.
However, what are the differences on the rear seats? I'm not saying you're incorrect, just wanting to understand the differences. I've never verified the two side by side. As I think of it, here are some differences I can think of...
1. head rests - remote release on S60. Manual release on V70.
2. lower seat cushion - is the V70 differnt to accomodate optional integrated child seats?
3. different rear of the upper cushion. V70 more visible from the boot. Upper LATCH anchors.
4. S60 has pass through trunk door on upper cushion. V70 doesn't (at least mine doesn't); it only has 60/40 split fold down.
5. back side of upper cushion on V70 has cargo net on my wagon.