Most likely not. LMGTFY... just kidding. Check Visa HQ to confirm but we are pretty sure you are good to go. We just want folks to come and enjoy this beautiful country... oh yes... and I guess spend money too... :)
Well... I'm not sure either... why don't you take a couple $100 and waive them around and see what happens :). The truth is that it is safe for international standards, but not quite the US. I would encourage folks to keep an eye on their possessions, and not to waive money or valuables in public. Other than that you should be good to go!
Tuxedos for men (but some stylish folks can pull off a black suit with a black tie). Women wear formal long dresses (typically with high heels).
Easiest flight is probably American Airlines (via Miami), LATAM (via Miami or NYC) or Copa Airlines (via Panama City). Delta (via Atlanta) is also a great option if you don't mind staying over night in Quito - you can either get to know the city or stay at the Wyndham Quito Airport Hotel. Avianca.