Hi , It takes about 3-4 seconds here for your demo website to start loading …
Also my theme got soft-rejected before because of this validation error
“Bad value https://api.w.org/ for attribute rel on element link: The string https://api.w.org/ is not a registered keyword.”
I believe this was fixed in WordPress 4.6.1
Also you demo website is working just fine here with no missing assets at all ( no broken links ).
Good luck .