Creation of Blank CR for MDG-S

Hi

I need to need blank CR (Without proving any value for Mandetory fields also but with CR Description and Attachment).

For this I selected BP Role BBP000 and assigned to Vendor Account Group 0001 .We are using Vendor Like UI with template WS5310044.

I do custimation in Configure Properties of Change Request Step for Step 00 as per below

So every error message converts to warning message and I can able to submit CR as Reqestor.

Here are few questions

1. Is it possible to make Account Group field as optional in Vendor Like UI? so  that requestor need to provide only CR description with attachment only.
2. Even if requestor provides Account Group as 0001 then I can see error messages converted into warning messages as per below

But when requestor selects attachment tab to attach file all warnig messages are converted back into error errors as per below

How to achive this in this case?