I will likely push him to the customer center and wash my hands of it; just scared of 'touching' credit card information

Prolecto has a bundle that does exactly this. http://blog.prolecto.com/2016/09/25/accept-credit-cards-without-a-netsuite-web-site/. I am no PCI expert, but as far as I understand as long as your suitelet puts the credit card fields directly in the payment record fields you are fine, because NS is PCI compliant.