Hello,
1) Add the footer static block to footer widgets https://prnt.sc/26qaztx
2) I don’t see a lot of space between products in the cart https://prnt.sc/26qb0u0 Could you provide screenshot of the problem for better understanding?
3) You can manage locations from XStore > Sale Booster > Fake Sale Popup > https://prnt.sc/26qb1vx
Regards