Kashrut - ingredients declaration

Question

Hi I see from previous responses that the Rav seems to hold that one can make one's own decisions if ingredients listed for a product are checked carefully. In the past, although we've always kept a kosher kitchen, we have relied on checking ingredients with a very limited number products e.g. a vegetarian (liquid form but mass-produced) soup listing kosher ingredients is one. Nothing we've used has had a non-kosher ingredient listed. We have opted to be stricter with ourselves now and check for hechsherim. However, given some of the responses I've read on the site, am I right to assume that we have not inadvertently made our kitchen plates etc. non-kosher by having in the past very occasionally relied on an ingredient listing and not a hechsher? Thanks for your time.