BuddyPress.org

Hello

Wordress 4.1.1
Buddypress 2.2.1

I have two issues with the members registration.

1. I would like to hide the username on the registration form. I would like the user to register with his email, lastname, firstname. I created a firstname field and I use the name field as the lastname.
But I can’t remove the username. I understand that this field is mandatory and very useful for wordpress so it can’t be removed but can I hide it? or fill it with a random value?
I tried to put the email address as the username but after it is used in the URL of the profile and I don’t want the member email to be displayed.
For me the better solution would be to fill the username with a random value and replace it with the user_id once the user is created but I don’t know how I can do this.

2. On Buddypress if I understand well, it is the display name which is displayed everywhere. How can I insert in the display name field the name + first name I ask in the regsitration form?

Thank you very much for your help.