Artist and graphic designer change of APE code?

I am an artist, painter and graphic designer who declared a business on 0703/2012 as a pro liberale APE 7410Z Activités spécialisées de design. I chose this for a prospective client who wanted to avoid paperwork declaring TVA through MDA. My French partner was frustrated because I was no longer under his insurance and carte vitale. He said RSI are not as good or quick at reimbursing. And because I had to start paying quarterly into the system before I generate revenue.

The client fell through. After receiving many demands for cotisation from RSI and URSSAF, I went to URSSAF 31/10/12 where ‘ils ont radie ‘mon compte cotisation d’allocations familiales’ avec effet du 07/03/12. They sent me to MDA to get questions answered.

I have a number en veille at MDA due to a previous start that I annulled. MDA encouraged me to stay and declared me assujetti(e) from (01/07/2012 to 30/06/2013). Strange as I have not generated any income. Is this why I have to send back a declaration for the year stating I have made zero income? Then supposedly all will be closed.

Now I have received income from a client for 2013, so what business to declare? URSSAF says they decide( MDA or auto-entrepreneur). Can I just stay assujettie with MDA? Do I need to declare a start of business again? When do I need to declare this income?

Advantage to MDA I’m told are that I can remain under my partner’s regime sante and I don’t have to pay into regime until end of 2013 and can avoid altogether if my expenses balance out my revenues.

Will my clients be obliged to declare through MDA or can they avoid this? I’m afraid I will lose work from small clients. Is MDA better than auto-entrepreneur? URSSAF say I cannot change to auto-entrepreneur until 2014, but I heard if I change my APE then it is possible. What do you recommend?