Can I delete my current Yahoo account and create a new one with the same Yahoo id?

When you delete an account, it is reserved for up to four months in case you shout "I want it back". So it might take longer than that to clear that name. If you just want the same YA user name, you can do that anytime.

It will not be available for some time, but you can open a new account with a small adjustment of the address.

Yahoo phone help answers are scams.

Currently posting as - 1 800 ☏ 782 ☏ 3911

You can only create a new account with the same ID if and when it becomes available.

Doubtful. If you delete your account, the ID is probably reserved forever. If it were not, an identity thief could create a new account as you describe, then wait for emails to come in from long-lost contacts.