The two of these are common English expressions. You may use them interchangeably but you must take note of the context of the sentence. URL: http://teacher-keith.blogspot.com

In a legal proceeding, those expressions might also occur in testimony. Let's say an investigation is looking into corruption at a high level, seeking to know who knew what when. "Did anyone mention the transfer of funds to the Contras?" "Not that I recall."

Yes, it is common in informal speech. You wouldn't say it though in a professional environment e.g. when you're talking to your boss, as it appears you are avoiding the problem and not tackling whatever is presented.

Yes, they are very common phrases... not that I can recall when I last said them. :)))))))