Excisable invoice

Dear Experts,

I am working in a Food Products Manufacturing company, we have both excisable and non-excisable products.

1. Is it compulsory to prepare Excisable Invoice for Excisable Products?

2. Can Both Excisable and Non-excisable products billed in Sigle Invoice?

3. Is it compulsory to disclose Excise duty and cess in Invoice?

Since our all distributors are traders, they will not get CENVAT Input credit. Hence can we make invoice without excise duty showing in Invoice but caclutaing back-end in the software for Duty payment to department.

Kindly advice on the same...

Thank You...