Tax Invoice vs Receipt

Hi All, 

My company is not a VAT registrant. However, my accountant is keep arguing with me on below matters. I'm unable to find any information from Mr Google, hope someone from here can help me out.

1. Company bank information, customer's mode of payment (cheque/cash/credit card), detail of payment received

   Is the above information a must to indicate in the invoice? I thought this is up to the company preference to indicate in the invoice or drawn it in the email when sending the e-invoice / payment reminder to customer? 

2. Official receipt 

    Since i'm not a VAT Registrant, do i have to issue a official receipt? Is it offences if not official receipt issued? Is this must have documents or good to have documents? Is this document must be generated from the system? can this be using pre-printed official receipt if the system can't print out this document?

3. Signature of Authorized by and Collected by

   Is this a compulsory? Can i just put up a clause "This is computer generated invoice and no signature required"?

Thank in advance