1. Actually we’re not recommend to you to use automatic update for those plugin, because if you use new version of those plugin that not compatible with JKreativ it will break your site. Please still use those plugin version that come with these theme for compatible reason. We’ve been adjust those plugin to fit with JKreativ.
2. I’m not quite sure about that. It’s should works fine even you manually installed those plugin. I’m also install JKreativ on my local server and when i try do manually install those plugin there is no problem on my side. You can find the those plugin file on jkreativ-themes/plugin/js_composer.zip