I was inclined to stop reading when you mentioned /RDM; but i proceeded on.

tanking WKR and Delve 1.0 can be done by almost ANY job, I have tanked all WKR on SCH/RDM while nukeing and holding hate (better then the plds because t1 nukes can deal 1.5k + or more and you can spam them), I have hold/tanked Delve 1.0 bosses on SCH if something went on the downside.

Unless you are talking about Hardmode Mission battles D or VD stuff or Delve 2.0 stuff, its not very good information (albeit still info). None of the stuff you mentioned hits very hard for a decent/good geared players that knows what they are doing on their job (PDT/MDT sets etc.). Hardmode mission battles on D and ESPECIALLY VD are a different story. i would like to hear how you handled those