Hello,
Thanks for using our theme.
1) Enable Elementor for static blocks https://gyazo.com/df82a85719ad793c2a6a7319d5f4435f , then edit the Footer static block using Elementor.
2) Yes, because Multiple headers are used. Go to Theme Options > Header builder > Multiple headers > edit the header for the Front page. Watch this video – https://youtu.be/BpeXfzNwkOc
3) All options work on our test site. For example – https://gyazo.com/efab8ba291647bcdf9d745d6a8f86c89
Please provide temporary wp-admin access, so we can take a closer look.
4) Theme Options > WooCommerce > Shop elements > Sale & Out of Stock > Show Sale Percentage > On and Show Sale Percentage For Variable Products > On
Regards