Checkout.liquid is deprecated and limited mainly to Shopify Plus legacy stores.

Yes, heading and body fonts can be selected.

Yes, some branding applies to both checkout and customer accounts.

It is Shopify’s interface for customizing checkout and account pages.

Yes, many settings are available through the visual editor.

Yes, through checkout extensibility and approved apps.

Yes, merchants can switch layouts from settings.

Yes, through Shop Pay and browser autofill.

Yes, Shopify mobile apps support checkout settings management.

Yes, uploaded images can be changed or removed.