Hello,
How can I set sortable grid galleries in the pages, either in portfolio sortable or full width templates?
Following tutorials will be helpful to you to create Sortable Portfolios,
How To Create Different Layouts In Designorbital Themes
Recommended Method To Use Custom Post Types Widgets In Different Layouts
How can I set my menu to look and work like this one from the link below?
You have to play with CSS to clone the menu of your example. I have forwarded it to the developers who might be able to share a code with you.
The favicon looks pixelated, specially in the iPad retina display. Is there any way to make it look better?
Following article will be helpful to you to understand the concept of High Resolutions Favicons,
http://davidwalsh.name/retina-favicons
Thanks