Does anybody use bare .SWF files as webpages?
I know it's possible; it seems to work fine for me.
Why would I embed a SWF inside an HTML page if it's just going to be full screen (I mean the size of the browser's normal viewable page area, not COMPLETELY fullscreen)?
Is there a lack of browser support?
Or is this functionality determined by the browser's Flash plugin?
My opinion is that if the browser has the Flash plugin it will render it, and it's up to you to implement how the swf behaves when you scale/resize the browser window/etc.
You can embed a swf in an HTML page and have it full browser screen offcourse, and you could interact with the browser a bit better ( some nice javascript/flash action going on ), not mention it would be more SEO/standards friendly.
I would recommend using SWFObject. Have a look at the fullpage demo.
If you embed it in html page and the client doesn't have the flash plugin, most browsers show a missing plugin message. If u directly host the swf, a plugin-less browser might consider it as a download link and try to download the swf into the client machine instead of showing the missing plugin message.