I "think" you can use the SYSTEM EVENT "Effects are Supported". Then (if true) add the ACTION to go to your game layout. If not, then load a layout that says something like "This game uses WebGL effects, please use a browser that supports WebGL such as Chrome" - with a nice link or something.
I am going to try that as I only want my game to run with WebGL effects.
Not sure if his will help with your audio "check list" - but maybe it will get you closer. <img src="smileys/smiley1.gif" border="0" align="middle" />
There is probably something in the CSS/HTML/Index file that could be modified too - but that is beyond my skill set. lol