Yes, this is somewhat misleading and will be fixed shortly. API key/API secret is the Amazon way. For Rackspace and Linode just put your username in the API key field and your API key in the API secret field :)
Pricing policy will be published pretty soon. There will be 4 tiers depending on the number of managed and monitored servers: free, basic, startup & enterprise.
It will also be possible to get self-hosted installations with support.
I don't think there is another WebFWD III project licensed under the AGPL. We chose it to in order to allow people to use and customize our code but prevent competitive services built on it.
If you need a special license for your project contact us at founders(at)mist.io
WebFWD is an awesome experience! It's helping us turn mist.io into a solid business with a great product, without having to give away any equity. The mentors are top notch and very engaged in the whole process. Being a part of the Mozilla community is the best thing ever. If you're working on an open source startup, complete the short application form now! It's totally worth it.
The initial feature set is that you'll be able to create/destroy/tag/reboot and send arbitrary ssh commands to your VMs from your phone, tablet or laptop at no cost. Monitoring and sms/email alerting will be available for a small fee.
We're still working on the user interface so we're not quite ready to publish screenshots yet. Check back soon!