I'm sorry to hijack this thread. But I have the same dilemma.
Not really sure what to use if setup with First Payment or setup when manually accept pending order.
As mentioned in this thread, the order will remain pending even if it is paid and I understand the logic as mentioned by DAN.
However, this is my problem, when the account has been setup, and payment has been completed, and when I tried to accept the order, I get an error saying that the account has been already created. Therefore, I am unable to accept any paid order..
I am not sure if this is a problem with WHMCS or with the module I use. By the way, I use CWP with their own WHMCS module.