Appointing sponsoring Spouse as Unpaid Representative

Spousal sponsorship: 2 questions: Q1: Is it a good idea for the applicant to appoint her sponsoring spouse as her unpaid representative, or any other suggestions? Q2: Applicant is doing the application by herself. She wants to put her spouse as her representative and fill out the use of representative form. But, on the Generic application form when it says to use the same email as the account is made with, which email should be put in? Applicant’s or her sponsoring husband, who is her representative?