Vanilla's mobile version loads quite fast even on an edge connection. But how to see the search box or the various categories and tags list? Thanks in advance.
if you want to modify the mobile theme. I would think you would need to do something like this.
create your new mobile theme according to the guidelines for writing themes.
(modifying default.master.tpl in the theme's views directory.
then point your new "mobile" theme to whatever you created in conf/config.php
$Configuration['Garden']['MobileTheme'] = 'newmobile';
I may not provide the completed solution you might desire, but I do try to provide honest suggestions to help you solve your issue.