How does information about domains get to parent DNS servers?

Question

Domain Name System

Dear colleagues! I didn’t really find good descriptions of how DNS works, only fragmentary information. I understood almost everything. How requests are cached, how they are redirected to areas of responsibility, is generally clear. But please help clarify the following:
Example: I registered the name name.ru, for which I provided my data.
1. If I don't delegate the name yet (i.e. don't associate with any ns servers). How does it get information that the name is already taken? those. in who is.
Will the parent servers of the .ru zone (a.dns.ripn.net, b. ... f.) know about this? How will they know about it?
2. In order to delegate, I specify ns records hosted on a free DNS hosting server, but do not create A records yet.
How does this information get to the parents? and how fast?
3. Now I point A records to a specific IP address. How does this information get to the parents? and how fast?
4. How are erroneous records in dns servers controlled? For example, in the registrar's control panel, I specify two different DNS servers for my domain. On one I make an A record to one IP, and on the second I make an A record to another IP (I made a mistake). What will happen?
I also fiddled with nslookup, and found an interesting "Free service for checking DNS" adivodns.ru

Answer 1

you forgot what is in front of ru .
and even goes according to the principle
.
ru
site
so that's the point know what for such a domain ru
and ru know that the site is busy