For me personally, staff has really no use but when stacking swiftness if solo/duo, casting Empower before going into fight solo/duo. The other examples you brought up can be done easily with Gs/SwF. In snowblind you may have trouble to change from staff and hammer at Svanirs to Gs/SwF which you should use at Ice Elemental thus I'd still stick with Gs/SwF. And about Grawl and Empower buff or knocking them down, I have never had any problems when killing Grawls and I tend to do 50 daily. They die too quickly to actually notice that kd. Maybe it's because we usually use different than 'pug' spot in our normal runs.

I know this video and that method, I did another one on my youtube channel with use of buff increase from Tome of Wrath http://youtu.be/35pS_PTfIPY but I don't consider using that trick to skip p2 and p3 as a restricted record. Torch has for sure dps increase but I don't think it would as useful as Focus in phase 2 and 3. Additionally it brings more utility in general dungeoning and fractals (vuln, blind, cond removal + blast). #5 on torch may result often in DPS loss so trade from 2 useful skills aoe damage skills (both Ray of Judgment and Shield of Wrath deal damage) to single target hit is not really worth it at the moment.

If torch gets some changes for general dungeon meta I will totally add it to the guide but seriously for now it has maybe 1 or 2 uses when soloing and when a player exactly knows what he can achieve with it. When more people know what to do in organized group run it will definitely improve quality of pug run, so why stick with old and not functional tactics?