Also, has it been established that off-hand strikes can be dodged/parried separately from main hand? Ie. lower OH expertise might not even matter if the offhand strike always connects if the main hand one does.
I guess that doesn't give as many details as I thought but yes at a high gear level there's barely any difference in using unholy runes or not depending on how good you are with ams soaking, pl, and bt. Although you still use plague strike to keep up blood plague
Obliterate can go either way, there are top ten ranks with and without it.
Soul reaper is a dps increase. About a 0.3% dps increase in bis gear.
Soul Reaper, while an increase, is a shell of its former self. This has been my single biggest disappointment with the class in MoP. I understand the need to adjust it for PVP balancing, but in PvE DW with enough mastery, Soul Reaper is an afterthought to a good proc run.