I will explain simply, like this, comparing a simple part of your site with the way it should be done. Now, I'm not saying that my way is the only way, or that you couldn't do something more simple, but your way is wrong. It doesn't represent the data you are trying to convey. Not properly. How does a computer see your code? It sees a table, so it presumes you are working with tabulated data, it sees bullet points that mean nothing to it. It doesn't convey the data well in any way except visually, and even then it does it in a half-hearted way.
Using tables for layout, using depreciated tags and code that is mangled and wrong - that's not experimenting, that's a lack of knowledge and use of outdated methods.
Please don't try and defend the site. I know I sound like I'm being a horrible person - I'm insulting your work, and I'm sorry - but the reality is it is flat-out-bad and you should work on improving it.