Hi Cavid,
Leverage caching the fonts depends upon your server settings. You can add few code in your htaccess file to ask the server to cache the font files as well. As of now your server is leverage caching for images, css and js.
This thread should help you. https://stackoverflow.com/questions/26553140/how-do-i-leverage-browser-caching-of-woff-fonts
We are sorry but we don’t have the font weight variation system. You can directly set it via css for your elements to make it bold.
Thanks