Never knowing the other persons intentions and then the intentions turn out to be not what you want.
You're either fine with it or you're not. Its not a hard decision.
They turn out to be gay.
Yoda has never had this problem. Though perhaps being friends may help you meet people.
You liking them, but not their lifestyle choices.
Again, you must accept or reject this. Are you looking for something long term? Yoda normally does not care for he will not know them long.
You liking them but them appearing not to like you.
Again, it is either finding out, or moving on. It is not that hard.
Them liking you, but your not attracted to them.
This is a clear no.
Are you telling us you are indecisive, do not like saying no, or don't think you can find anyone if you move on?