Hello,
1) Footer inherits you container width that you set in Theme Options > General > Site width. So, if you want to increase that then just change that width to 1500 for example.
2) If you want to have off-canvas once you click the cart from mobile then the cart element should be in the mobile header https://prnt.sc/21eibi3
In case you don’t want to show cart in the header then you can hide it using below custom in Theme Options > Custom CSS
.mobile-header-wrapper .et_b_header-cart {
display: none;
}
Regards