Hello,
1) I added below code to Theme Options > Custom CSS to hide mentioned selects
.filter-wrap .products-per-page, .filter-wrap .woocommerce-ordering {
display: none;
}
2) What do you mean that buttons do not work properly? It switches between layouts https://gyazo.com/1bab5a0067d9a33ad3c6050debe1a98a So, could you, please, provide us with the screenshot for better understanding.
If you want to set grid only you can do this in Theme Options > WooCommerce > Shop > Shop page layout > Products View Mode.
Regards