Good morning,
How I love to hear the Vitae Minor warble in the mornings. :D
As Scott already pointed out, you should start by looking at the Java scripts of the component you added. The problem is that you have been doing changes to the page in a way that is not controllable. Did you add the component from the Sidekick or did you add it in the Page component?
If it is the later, you can always use CRXDE Light and look at the page components and look for the last jcr:created and take that one out of the paragraph. We have seen this behavior when the RTE has been used and an empty, non-ending <a href=""> is there in the markup. The author environment don't seem to like that at all. See if you have anything like that in your code.
You asked about how to debug this things. "It depends", is my answer. Depends on what you are currently changing. If it is the markup, just use a LINT tool to verify that it is OK. If scrips, there are a lot of tools out there do debug the code. Then we comes to the hard part. You can't expect a system like AEM to handle all your problems and point out exactly what you have done wrong. If you don't use a tag the way it is supposed to be used, it is hard for the system to even start to realize what you want to do. It would be extremely expensive to develop a system like that. So expensive that no-one would use it... Well, then we solved the problem. ;)
When it comes to compiled code, like Java, it is easier to at least verify that the code in itself is correct, but it still might have logical errors. With markup we have other problems. Much of the code is executed on client side.
In the end, it comes down to the experience of the developer.
