Hi please first can you update your theme style.css: download this https://themeofwp.com/alive/wp-content/themes/alive/style.css and upload to your own theme folder (wp-content/themes/alive) logo and header height will be turned as logo height.

Also you need to define a background image or color for when scrolling from admin options http://studioflatland.com/wp-admin/themes.php?page=optionsframework at header options. It will be turned normally. (you will see the “Header Scrolled Background Color” section in theme options.)

Also yes you’re true, when hover the portfolio item it’s not compatible with only safari. We’ll be fixed this for safari soon.

Thanks for contact with us.