Carlos, that’s a whole pack of questions. I’ll take them one at a time.
The very first trust anchors will be invited by the Sovrin Foundation, yes. But then trust anchors will be able to invite other trust anchors in a web-of-trust model. This rooted web of trust design is being developed by the Sovrin Trust Framework Working Group, so please do engage there if you are interested (I chair that WG). We’ll be publishing draft documents about it later this month.
See this answer I posted yesterday to another of your questions. I think it answer this one.
Only for creating new identities for OTHER identity owners. Every identity owner can: a) create new identities for themselves, and b) write claims for any of their identities.
Again, let me know if my other post already answers this question. If not, just post your new question here.