It depends. Generally nostr is not about privacy. You sign everything you send/post, so once your identity is revealed, everything can be said to be yours cryptographically.

Also this means, everything you post or do with 1 "account" will be connected. So you shall keep this in mind.

Now, if you create multiple accounts and separate different things for different accounts, then it will be harder to attribute everything back to you.

If you nuke an account, and you create a fresh one, and you do it differently, then if anyone came to know your identity on your first account won't be able to use it any more, because you nuked that account.