Paypal and Stripe options on product page

There are now options for paypal and stripe on the individual product modification page, under product data.

Those options have always been there and are not new to either of the plugins.

Do these need to be checked? 

Only if you want to make product level config changes. You can make global settings on the payment gateway’s settings page. The product level settings exist so you can make customizations per product if needed.

it tells me the site has performed a critical error.

Go to the WooCommerce > Status > Logs page and there should be a fatal-errors log file. That log file should contain why the support request failed.