Speeding up SQSP 7.0 site - removing js, modifying CSS

Please see some metrics of my website at https://www.webpagetest.org/vitals.php?test=240425_BiDc0T_951&run=2 . Positions 2 to 13 seem to bloat the site quite a bit.

It's a 7.0 site using the Wells template. How can I speed up the loading of the site? Is it possible and advisable to remove some of the js or are they all necessary? 

Many thanks, I appreciate your help

Unless you've added javascript code, there's nothing that you are able to remove, it's all part of the platform.