I know exactly how you feel about the lack of simple support for common text documents.
When Deep Zoom Composer outputs its files, it should publish an HTML page in the same folder. If you open that with a web browser, you will find that it has a Deep Zoom/Seadragon viewer embedded in the page.
I don't remember whether the viewer fills the page or is smaller, but if it is smaller, you can open the HTML page with a text editor, edit the width and height of the viewer, save the page, then refresh or reopen the page in the web browser.
If you upload the deep zoom images to the web, you'll need to use a service that allows all the files and folders to stay in the same arrangement relative to each other. (In other words Skydrive is not a good solution because it uses such strange and unpredictable URLs.)