Hi Vishal
If you turn off SID generation in your DSO then it not have any impact if the DSO isnt used for reporting. So you can presume here might be atleast 20-40% reduction in the activation runtime for each DSO.
Secondly to reduce the runtime you can create secondary index for the DSO and ask BASIS to refresh stats
Thirdly you can increase the parallel processing for the DTP so that the runtimes get opimized
You cannot use WO DSO in your scenario as you will need delta records for your cube
In you landscape if you have BIA/BWA then enable it for this cube
I see you havent used PSA deletion in the PC so I am presuming its been taken care already part of your weekly/monthly housekeeping activity. Also look for change log deletion of the DSO
Thanks
Abhishek Shanbhogue