i think for pve you will not take the 10% reduction glyph, ofcourse its still good there but most dmg in pve is avoidaable or you can time your BS \ SI for it
as with moonfire, it all depents on what the numbers are going tobe, we have no idea about that atm
if it has a higher DPE then shred (and its even ranged) then this wil give us yet an other dot to keep track off
if its DPE is lower then shred, it will probely see verry few useages other then a fight with a ranged part such as ONY (or pvp as some classes dont like tobe in melee with a kitty)
a small side note on the SR topic, i am quite sure SR will not buff moonfire as its arcane dmg,
so if it isnt buffed by SR, then it means moonfire either needs tobe verry strong baseline or it will never have they higher DPE then a shred that gets buffed by 40%