Hi there!
1) Is it possible to increase the number of options on the payment screen?
For example, you can select a color variation.
Do you want to offer variation options on Checkout page? With variable products, you can create options for customers to select on product page. Here’s more information on that: https://docs.woocommerce.com/document/variable-product/
If you’d like to offer these options at Checkout, you could look at Checkout Field Editor https://woocommerce.com/products/woocommerce-checkout-field-editor/ to add custom fields to the page. Note that you won’t be able to manage stock for each option if you add them on Checkout page.
2) Is it possible to change the order memo message?
Would this be the text on the Order Received page: https://d.pr/i/ZKOYbh ?
