No, WHMCS cannot import these accounts and packages automatically, however, you can manually enter them into the system from the admin area with all the details exactly as you want.
So if I was to have created an account alrady in WHM called "account1", and let's say it is temporarily accessbile at:
http://www.mydomain.com/~account1 (although this is not important)
can I then create the same package and account in WHMCS and it will then control that original account created in WHM?
Apologies if that sounds completely wrong, I'm just trying to get my head round how the system works
Yes it is possible. For each package you create, you can create and assign an unlimited number of addons to this package. The customer can then order these addons for the package directly from his/her client area as they need them.
If I created a package with addon domains in it (say 3) would the client whose account uses this package not then automatically have access to those addon domains?
And if I created a package with none in it, and they request one, if I were to add an addon domain to the package, would that not automatically effect any other account that uses this package?
Or does it not work like this?
Yes, you can do this. WHMCS will support any products you wish to create, not just hosting so you can offer website design services, template packs, script installations etc... There is no limitation to the services you can offer and you can create a custom email message sent when each different type of product is accepted so you can make the system work for you how you want it to. Products can be set to have a One Time fee and as such will be invoiced just the once.
Great, thanks
Does all the above make sense?