benefits and EEA family permit application

[jam2011]

hello,
i am a NON-EEA national and my wife is an EEA national and iam going to apply for an EEA family permit from my country, but my wife is getting:
• child tax credit;
• working tax credit;
• child benefit;
• housing benefit;
1)does this affect my application?

my wife was working in the UK for the last 3 years, no she is working with agency and she is doing an average of 25 hours a week.

2)
is working for an agency bad for my application?
3)
how much money she needs to show in her bank statement/ is the bank statement required for EEA FAMILY PERMIT application or her PAYSLIPS are enough ?

thanks for your help