Previous Home Xbox

No, it will not take it off his Xbox. Only way you can take your account off of his Xbox is to go onto his Xbox and take it off yourself. If you don't want him to use your account, then I suggest changing your password that way incase he tries to sign
in to it then it will ask for the new password.

Do you mean like your account off if you make your xbox the home xbox he can't play none of your games

It won't force your gametag off of the "account" section, but if you set your console as your home you'll cease sharing your game library with him and if you change your password on your account they won't be able to access it since they'd have to type in
the new password if they selected it.

No, if you remove your friend's account, you will not only see his account in your xbox and his friend will be able to see your account, if what you want is that his friend does not enter your account,
then you would have to change the password of your account. Having an account as "main" will only make games shared, if you change the main account to yours then you would only have access to your account

Hello,

When you change home consoles, all device licenses for digital content will move to your new home Xbox. These device licenses will no longer be available on your previous home Xbox. In other words, when you switch your home Xbox, access to your content
comes with you to your new home Xbox, and anyone signed in can enjoy it. Your previous home Xbox will still give your friends and family access to your stuff when you’re signed in to it.

https://support.xbox.com/en-us/help/hardware-network/console/my-home-xbox