Commission income, change in itr form

Hello Sir,

I am having following queries - 

(a) I am having commission based business of dress material / Kurties and other seasonal item running from home. So which business code I need to select in ITR-3?

(b) My earning is anywhere between 175000 to 25000 p.a., do I need to update P&L / Balance sheet or I can continue to mention in schedule BP A24 in ITR-3

(c) If I will accept full time job and leave this business then do I need to shift from ITR-3 to ITR-2 considering I have other source of income from interest & capital gain from equity?  

(d) If I receive every month some amount from my husband directly in my bank account, can I mentioned this as salary in schedule BP - A24 (a) Salary or it will be consider as Gift?

Kind Regards

Dolly