There are many different approaches to XSS that are secure. The only why to know if your approach holds water is to test though exploitation. I recommend using a Free XSS vulnerability Scanner or the open source wapiti .
I think what you're doing is safe, at least from my point of view no html code should get through your filter.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.