Yea. The only way to get this possibly working would be with the help of some symlinks (or perhaps simply hidding the files would suffice?).
Anyways. Of all the files you listed, nw.pak and icudt.dll are the only absolutely manadatory ones (well. nw.pak is. I haven't yet tried without icudt.dll, but since it's a networking library, one might even exclude that one as well).
dxwebsetup.exe can be placed into a different folder (most studios place them into a folder called setup or install or extras or something to that avail).
ffmpegsumo.dll is used for <audio> and <video> tags, so you only need them for apps using the audio/video capabilities of the browser (to be fair, most games probably need the audio tag, at the very least)
libEGL.dll and libGLESv2.dll are used for WebGL and GPU acceleration
D3DCompiler_43.dll and d3dx9_43.dll are used for the compatibility layer (to make sure that WebGL games run on non-WebGL compliant hardware).