CSV Upload for users - Moodle 2.9.3

I'm having difficulty with a couple of aspects of uploaded CSV users.

1. What happens if there is an error in the email address of the user in the CSV file?
2. The welcome message goes out from me.  I set up the Moodle and am an admin.  However I am not the main admin and I understood that the email went out from them.  Is there a way to change this.
   
   Finally;
   
3. I've edited the language pack message but the formatting is awful:
   
   

   A new account has been created for you at 'name of moodle site' and
   you have been issued with a new temporary
   
   password. 

   Anything I can do to make this look better?

Thanks

Dave