Understanding Centre de Gestion Agréé and cotisation charges?

I am using a well known firm of accountants to compile our end of year accounts and tax forms. I am thinking of finding a different company for 2015, because the contract includes paying an additional fee of 150 euros per year, to join an association called Centre de Gestion Agréé. They have not explained why this is compulsory or what it provides for us. I am in year 2 as a cotisant solidaire reel with MSA. Can you please explain:

1. How we benefit from joining this association?
2. Can we choose not to join, if it is not going to benefit us?
3. Can we just use the Centre de Gestion Agréé for our end of year accounts and stop the 2000 euros per year contract with our accounts.

For 2013 my turnover was 20,000 euros, costs of 22,000 euros and therefore made a loss of 2000 euros. I have been told losses can be carried over for up to 4 years.

1. What will happen if I never make a profit?
2. Will I still have to pay cotisations, even if my business is making a loss?
3. How do I calculate the amount of cotisations I will have to pay, if I have not made any profit, or is there a standard minimum amount whatever your profit or loss.

I have not yet received any cotisation charges from MSA, since changing my business regime in 2013 from a BIC micro to a cotisant solidaire reel. MSA owe us 3500 euros for a 2012 cotistation overpayment. I do not want to receive a large unexpected cotisation bill.