There are different types of constituent structures that can be conjoined by and. All of these different points of conjunction are valid, and they all fundamentally mean the same thing:
- [I like to dance] and [I like to sing].
- I [like to dance] and [like to sing].
- I like [to dance] and [to sing].
- I like to [dance] and [sing].
(To answer your question about to, as you can see it does happen.)
Usually, people naturally conjoin as far down the above list as possible, for the sake of brevity. For example, the content might force you to stop at sentence (2):
- I [like to dance] and [hate sitting].
However, repeated information in a sentence is never incorrect on its own. One might choose to include some redundant parts for the sake of clarity, for emphasis, or for aesthetic reasons (e.g. it sounds better or fits better metrically). This can be appropriate both formally and informally, and is done by everyone in certain situations.
(If you made sentences like 1-3 all the time, where it is not necessary, it would probably come off as odd though. As I said, usually the briefest version possible is chosen.)