1. May i know what kind of blank option that you referring to? So i can easily to help you on this thing.
2. You just need to insert the page url into button url and make sure if you’ve enable the Show button on this slider item option.
Show button on this slider item
3. You can try to setup your logo on Customizer. For more detail please take a look right here http://jkreativ.jegtheme.com/documentation/#customizer-logo