your site slow, its not related with socialize template. mostly from your server ability.
your hosting is a dedicated or shared? if shared, the server resources will be shared with other sites that using same server.
I suggest you to increase server configuration (PHP, MySQL), you can asking your server support about it.
or you can try using
www.cloudflare.com
. but you must turn off any script minify or optimizer, that can make some jomsocial functionality broken.
