Do the doubts and delusions about the presence of someone seeing and hearing me, and the belief of hearing praise and admiration for my voice while reciting the Quran or praying, count as showing off (riya') or self-admiration, even though it is a recurring whisper (waswasah) despite seeking refuge from it?

These whisperings have no basis in reality, they do not distance one from Allah, nor do they affect the validity of worship. One must repel them and turn away from them. They are from Satan, intended to deter from worship, so do not let him gain control over you. Push away these whisperings and do not give them any attention. Strive to perform deeds sincerely for Allah the Almighty and ask Him for acceptance.