you can either migrate it or not its up to You.
You cannot delete a profile on Minecraft at the moment.
The email used for a migrated Minecraft account will be the same as the email used to sign up for the Minecraft account (unless you have specified otherwise). Go to Mojang's website to try recover your email if you cannot remember.
Use your email in the username box instead.
u can login with ur email
If you either signed up for Minecraft on Mojang.com or you migrated your Minecraft account, then use your e-mal address and password to log in to the game console. If you signed up on Minecraft.net or you have not yet migrated your account to Mojang, then log in to the console using your username andpassword. If this fails, migrate your Minecraft account to Mojang Remember that in order to successfully log in, you must own a premium Minecraft account.
Yes, you can log into as many minecraft accounts on one computer as you want.
No
Mojang does not currently support changing you Minecraft user name You can change your password on the Profile page of the Minecraft website You can change your email address by migrating your Minecraft account to a Mojang account or, if already migrated, go to your Mojang account Settings page As for creating an entirely new account, you just go the the Minecraft website and click Register, the only problem with this is you will need to buy the game again.
by going to the minecraft website and clicking on profile, edit character, then download the skin maker
By going on to the minecraft website and clicking on profile then press upload image and upload your image from there
You can change it under your profile on minecraft.net
You can sign in using your email if you have migrated your account to Mojang's website (linked below).