Add an "immediate login" Rule to Drupal Commerce, so that the anonymous user ends up logged in on checkout completion.
I plan to add the password choice during the checkout, I'm still trying to determine the best way to do it (see my question on Drupalcommerce.org Q&A).
Notes regarding the reasons behind the creation of the module:
- In my case, e-mail validation is not an issue, as the checkout is invitation-only, so the e-mail address has already been validated;
- In my case, the anonymous purchase is for an (expensive) membership, so forcing users to check their e-mail account is a burden my client wanted to avoid at all cost.