keldeo does not /need/ the raw power of hydro pump here imo, scald is a decent attack that can be spammed, and taunt helps beat bulkier mons. hp fire or hydro pump is upto you, if sd scizor is a big problem or not. since sd scizor can actually beat this team +2 superpower etc, i think hp fire/ the current set is p okay.
As I already mentioned, there are times when Scald fails to burn something. You
could spam it to fish for the burn, but it's just me, but IMO, more bulky Pokemon are better at relying on Scald's burn chance. Sometimes Hydro Pump is necessary to break through stuff:
252 SpA Choice Specs Keldeo Scald vs. 248 HP / 108 SpD Mandibuzz: 183-216 (43.2 - 51%) -- guaranteed 3HKO after Leftovers recovery
252 SpA Choice Specs Keldeo Hydro Pump vs. 248 HP / 108 SpD Mandibuzz: 250-295 (59.1 - 69.7%) -- guaranteed 2HKO after Leftovers recovery
252 SpA Life Orb Keldeo Scald vs. 248 HP / 108 SpD Mandibuzz: 157-187 (37.1 - 44.2%) -- 99.9% chance to 3HKO after Leftovers recovery
252 SpA Life Orb Keldeo Hydro Pump vs. 248 HP / 108 SpD Mandibuzz: 218-257 (51.5 - 60.7%) -- 91.8% chance to 2HKO after Leftovers recovery
Again, IMO, I like having Scald and Hydro Pump at the same time, the former for trying to burn things on the switch or can't afford to miss and the latter for simply breaking through things.