If I just take the Individual Query and run an estimated plan

Plan A: it does not show any suggested index's .. you start with a Clustered Index Scan (cost 74%), move to Sort (20%) > Parallelism (6%) > Select (0%)

This is the one that failed to execute in 20min.

No blocking showed up in the trace...

Estimated rows 28M, estimated cost 1,878, cashed plan 24b

All SPIDs of these SPIDs were executing Select statements.. the writes were going on in the SSAS cubes. (for the jobs) and the users were only doing selects.