when a worshipper finds that he is prone to showing off in acts of worship such as Salat especially in front of others, is it at all advisable for him to continue attending or praying at the Islamic Centers? also should he take precaution and not attend when the probability of committing the sin of showing off is very probable?

This is a waswasah from shaytan. A person should work to eliminate the showing off without having to stop going to the mosques or Islamic centres. In fact in most cases the prayers of the one who lives close to the mosque is not accepted in the home.