question

>>I keep accidentally deleting the title player instead of master player when testing... Then i cannot make a new account with that email, so i have to keep switching up emails.

Deleting a title player account (TPA) doesn’t release the login credentials as the login credentials are linked to the master player account (MPA). Therefore, you can’t create a new MPA with the same email. However, the MPA’s existence allows you to use LoginWithEmailAddress API with the email to log in again directly and it will create a TPA under this title again.

>>Is there no way to find a list of master players and delete them?

Currently, PlayFab doesn’t provide such feature, you may post a feature request for it.

>>It's strange, sometimes i'm able to login with these emails, then delete them, but sometimes even when i delete the master player and try to register again it says the email is already in use.

When you delete the master player account, the account will be queued for deletion, it may take some time for the account to be processed (the queue is not a queue solely for your title, it is a queue for all titles, and it will cleanup all elements of the account). Usually, it takes less than a few hours. Sometimes when the queue is busy, it can take days. So in your case, it should be that the account deletion has not been completed.