Years ago I changed the Microsoft account my gamer tag was tied to. I don't remember having any issues at all.
Currently my friend's account is constantly trying to be hacked. He has dozens of attempted logins from different countries a week, some actually get in. Changing the password stops the successful logins but we are still dealing with security change issues all the time. It's a hassle and turns our game nights into tech support nights at least twice a month.
We would like to move to a new account, one with an email address he actually uses now. This wasn't an issue for me a while ago but the Xbox One seems to lack this feature all together, so I am worried about doing it now.
Will he lose purchases, saves, anything like that? Is it possible to change the email address used to sign in and completely remove the old one instead and avoid any of this risk?