Maybe if you code it for us, we can understand better what you mean by in the tag and text with tags around it. I confess I don’t understand what you mean
the text inside the made-up tags displayed fine. So I think it largely depends on what you mean by “risk”
AFAIK browsers may use the tags for layout, but the text inside of them should display unless CSS or JavaScript is affecting them.
IMHO if the page passes http://validator.w3.org/ you will be more than likely be fine (and a lot better off than a lot of other site’s pages) in terms of the mark-up having any negative impact on display time.
Not to say that the number of HTTP requests, JavaScript, image size etc. won’t have an effect. But if you get the mark-up to validate you’re off to a good start.