A: I felt as though you could hit that target without me. (a simple statement of fact in the present about someone's ability) B: I felt as though you could have hit that target without me. (means that something was possible in the past or the person had the ability to do something in the past, but that he/she didn't do it)

The thought is more complete if you say, "I felt as though" or "I felt like" instead of just "I felt".

You could omit the 'as though'. It's not necessary. A. is just expressing what the person felt B. is also expressing what the person felt BUT with some regret or stating how things could have been different