How Should an UTG Range have played this hand?

While reviewing hands I played yesterday, I questioned how my UTG range would have played this hand on the flop.   My UTG range at a 9 handed table is fairly snug, AQ+ 77+, sometimes AJs.     Flopping a big, but vulnerable hand, multi-way with straight and flush draws possible, I decided to bet about 2/3 pot.    (The pot was actually $69 after rake) 

My questions:

Would it have been preferable to bet smaller in this multi-way pot?  

Are there any other range considerations I should be thinking about in the future when in a spot like this?   For example, would I bet the same amount as I did with KK if I held  AQo or 88 or AsJs instead?

Thank you!