1. Is the SCA addendum removed now that Microsoft announced the Qualified Multitenant Hoster addendum?  Yes.  SCA has been removed and replaced with the QMH addendum.
2. If I have a CSP Indirect/Tier 1 authorization, can I resell Azure Stack but license Windows Server through SPLA?  Yes.  You will pay the base consumption rate because you A) Purchased the hardware through an authorized dealer and 2) paid for the Windows license through SPLA.
3. If I am not authorized for CSP, can I still sell Office 365 to my end users?  Not in the general sense.  What you can do is resell CSP through a distributor or authorized CSP Indirect/Tier 2 partner. You can also partner with a CSP Direct partner to offer the solution.  They would resell the actual license but you can provide services on top of it.
4. I am a SPLA partner who wants to resell Office to my end users.  What are my options?  You can sell Office through SPLA and include RDS and Windows.  You can become CSP Direct authorized and use the QMH addendum mentioned above.  You can also use end customer owned Office licenses and host it in a dedicated environment.
5. Will Microsoft offer QMH for Indirect partners as well?  Not at this time.  You must be CSP Direct to qualify, not Indirect.

Lots more on this.

Thanks for reading,

SPLA Man