I'd also prefer to see Surf/Hydro Pump as the main non-STAB moves.
Same, because it's a cloud and clouds make it rain so it fits perfectly.
Why do people keep insisting on using flavour as an argument?
Oh wait, you just said....
Ha ha, but to get serious, wouldn't the fighting moves be a bit helpful for some of the said possible counters?
Actually, if you're aimin' to make sure this can't can't take on everyone, that makes sense, especially for this Cap, since so many other offensive possiblilities are still being debated.
*Edit*
Now to get at several choices briefly....
I support both Fire and Water moves for offense. Mainly Surf and Flamethrower. Coverage with em is great.
I also support Special Fighting moves. Hits well on a few guys (like Heatran and Tyranitar), and at the same time won't be unbalaced by some others who won't be much afraid of it at all.
Mist Ball is quite clever, but its power is not appealing at all. The effect can actually help, but the power (70) is far too low.
I see no real purpose for Physical Fighting moves. Unless, a practical way of raising attack is available, just pass em on.
SelfdDestruct/Explosion serves little purpose as well. It won't even work on the guy. You can be either slow or have low attack for it, but never both. Packing the move just for Blissey doesn't seem smart at all.