Hope you like people in you shots cause taking pictures on the strip is seriously difficult.
I live in vegas, and the best ways to take pictures of the city are from high up and away from the tourist traffic.
I'd reccommend the top of the stratosphere or the roof parking on various casinos.
You definately don't need a flash in vegas. Vegas simply has a lot of lights. And red rock is fairly bland to photograph. We have kind of pale blue/grey blue skies and usually crappy looking air from the pollution.
Yeah, if you can't tell, I don't like living here. Oh well, have to make due.