Yes you can apply for BR, however I would check with your IVA Firm to see whether their is a clause to say that they will hold funds to petition for your bankruptcy.
Likewise dependent on your debt and the level of debts, your creditors may petition for bankruptcy
If neither are they case you need to file for Bankruptcy where your IVA was filed as this speeds up the process a little. You will need your letter of termination, certificate of non-compliance and details of how the IVA estate was divided for the courts, you will need to take the original and the will photocopy it.
The other question is in my knowledge regarding to Benefits and as such are not counted as income