1 - It's a very good idea to have added that feature, but the user never receives the "pending payment" email.

2 - Paying offline in the basket:
- Most of the fields of the backend basket, etc are not in the translation file
- Activation email is sent in a language that depends on the language the administrator is logged in backend and not in the language of the corresponding user.
(eg. for spanish user:
if administrator is paying a basket logged in english, user will receive an Activation confirmation email in english. Not ok.
if administrator is paying a basket logged in spanish, user will receive an Activation confirmation email in spanish. OK )

3 - Info about invoices
In user Profile > Receipts (which is the invoices list), not paid Invoices are displayed with a field - Pending payment (Waiting for). But waiting for what? in the translation files, it comes from "waiting for %s" => "waiting for %s". Where is the %s??