This is just a preliminary post and I will be editing it once I get done fully analyzing your math and doing some math of my own.
I think one thing that your calculations are not displaying is that the DPS you do in a 8.0s rotation vs a 8.5s rotations accurately on a long enough timeline. The problem with the 2 slam rotation is that you delay the use of BT.
1.5 Slam → by slamming here you delay the use of BT by 1.5 sec
So letís say that you have a fight that lasts 5 minutes, which is 300 seconds.
That means that if you use BT the moment it comes off cooldown every time you will use BT 75 times.
And if you use WW in the same manner you will use it 37 times (37.5 but you have to round down)
WW has a 20% chance to proc bloodsurge, so 0.20*37=7.4 (rounding to 7)
That means that means over the course of the fight you will delay use of BT by 7 GCDs 7*1.5=10.5s
10.5/4=2.625 (round to 2) BTís lost by slamming after WW.
Now letís see what you gain:
Of those 7 bloodsurge procs, 20% of them will also see a proc from the BT. 7*0.20=1.4 (round to 1)
You gain 1 extra slam over the course of the fight.
2 BTs > 1 slam
Unfortunately these numbers are definitely skewed because of the fact that they do not take in to account bloodsurge procs from HS. When I get back from lunch I will see what I can do about possibly modeling HSís affect on the DPS comparison.