This is a very good moveset; looks like it functions similarly to DD Mixed Rayquaza in Ubers. Personally, I think Flare Blitz destroys the main physical walls (Forretress, Ferrothorn, Skarmory, and Mega Scizor) plenty well enough, especially after a boost, but running Overheat isn't a terrible idea.
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Also the only Pokemon I can think of that this would matter with would be Landorus T, who you can't even 2HKO anyways after the SpA drop. Every other physical wall is weak to Fire and gets obliterated just as bad with Flare Blitz.