Just a few quick questions :
Can WHMCS use 2Checkout recurring, by sending all payments with the product ID code already setup at 2CO? Lpanel does this. While it's impossible to track the recurring payments automatically, 2CO does email confirmation or negative payment. Since not many clients choose addons, it works very well.
How's the Paypal integration? Does it easily support one-time and recurring payments and tracking of?
I use a 3rd party helpdesk. Does WHMCS allow us to substitute its own helpdesk for ours, and give us variables which we can use, like username/domain/etc..
And last but not least..is there an Lpanel importer?