ILR application HELP!

[monk]

Hello.
I'm preparing the application form for SET(M).
I'm holding a spouse visa now.
I have two questions.
If anybody have any idea, please let me know!

1. Should I tick the Working Tax Credit box which my husband applied and when he filled the form he ticked "he has a wife". Therefore when he received NHS Tax Credit Exeption Certificate, I also received the same one.
Does it mean I'm receiving WTC?

2. My husband is self-employment.
Therefore he can't put figures on how much does he earn because every months the income is diferrent.
Should I put the figure which divided into 12 from annual income?

Thank you so much!
Lenna