In this sentence "请问，哪里可以买到票？" is the character 到 necessary? And can I just say: "哪里买票？"? This is what I used when I was in China and everyone seemed to easily understand. Is this shorter sentence incorrect or non-native sounding? How do native speakers ask this kind of question?
买票: is all about the act of purchasing a ticket.
买到票: is about where a ticket can be successfully purchased.

But the two are often used interchangeably.