Please let me know on which occasions should we use an unconditional stop.
This option changes the workflow status toFinished. This action should only be used as a last resort if the normal stop process fails after several minutes. Only use the unconditional stop if you are sure there are no actual workflow jobs in progress.
Also how can we check actual workflow jobs in progress on Marketing instance before we initiate the unconditional stop.
I did not understand well your question, can you explain more what exactly you need to know?
Also please let me know how should we debug a workflow which doesn't get into finished state but remains in stop requested state
Try to stop the workflow using Unconditional stop, then start it again.