I’ll concede your point on paying for the account, as I am not a Twitter user.
WRT the use of his own account, I would like to know why he can’t use it to make announcements to the public. This all revolves around a central question: does a person who is elected to be President of the United States lose their right to free speech or freedom of association? I would say that the answer MUST be “no.” Again, this is Trump’s own personal account, which was set up years before he declared his candidacy, won the election, or was inaugurated. He should have as much right as you, I or any other person to decide whether or not to ban particular people from commenting on his Twitter feed. He simply cannot lose his rights because he was elected to serve the people. None of these people are prohibited from commenting elsewhere (like, for example, their OWN Twitter accounts), and most certainly not by government edict. This is not censorship in any form whatsoever. This court decision was 100% wrong, and I am confident that if it is appealed (and it should be), it will be overturned. As I alluded to in my first post, this is his personal property, and having control of it taken away from him is likely and unconstitutional taking under the Fifth Amendment.
There’s nothing stopping Trump from having a personal account where he can say what he wants and block whomever he wants.
The problem is his @realDonaldTrump account became more than his personal account when his tweets became official government statements and he started to use taxpayer funded employees to maintain the account and tweet on his behalf.