Currently with the Falcon 9 they do the manufacturing in Hawthorne, initial testing in McGregor Texas, and then in Florida they have facilities for integration and inspection. They are leasing/building more facilities in Florida at Port Canaveral to handle inspection and refurbishment of landed boosters.

Eventually it might make sense to move final assembly closer to the launch site for BFR, but I would expect a lot of the component assembly (like engines) to remain in Hawthorne.

From [1]

>In addition, the lease would accommodate recovery operations undertaken by Space Exploration Technologies to bring to shore vehicles returning from space that are retrieved by an autonomous drone ship offshore.

So they would have the option of doing that at the new manufacturing facility (even though we can speculate that that would not be the norm).

1: https://www.reddit.com/r/spacex/comments/85i6rd/bfr_producti...

At first, but I believe the plan would be multiple flights per day with regular maintenance/inspection/rebuild intervals similar to how aircraft are maintained.