WHMCS MU Provisioning: clarification — and promotional code?

Before I sign up with WHMCS I have a few questions that hopefully someone here can answer:

1. By using WHMCS, will I be able to offer my multisite clients domain registration during signup, without having to become a domain reseller somewhere? This is a missing link in my WPMU system I’d love to add.

2. WHMCS.com lists many features, but during signup it looks like some of the most important ones are extras. For example, the Configurable Package Addon and the Android App. It feels like a bait-and-switch so it makes me wonder what else they are hiding until later. Am I wrong to feel this way?

3. During signup there’s a place for a Promotional Code. I hate seeing that and not having one. It makes me feel like I’m not getting the best deal. Anyone happen to have a promo code?