Hi,
It’s hard to really see if anything is going wrong from your screenshot as I have no idea what is on the page or the download times for the other files.
Attached is a screenshot demonstrating my own anemically slow internet connection and speed test in case it is of any use for comparison purposes.
The page loaded in 7.2s, stylesheet and jQuery in around 2s each, hover intent was about 1.6s but the superfish script was only 0.6s.
I don’t have the style.php file loading, but I’d assume it would be around the same amount of time as the superfish and hoverintent scripts.
This seems reasonable to me. The plugin scripts are executing faster than static files, albeit the files generated by the plugin are smaller than the static ones I was comparing them to.