ico?
afaik:
- No ICO planned, as everybody will be able to get some RDX for some of its crypto once launched.
- Early backers from previous private internal rounds will just have a bonus factor.

distribution?
afaik:
Elastic supply model and fees for the running nodes activities, managed by the decentralized Radix client.

I think it will be developped in future WP regarding client / economy etc.