Our use case is to send a document to a signer A, who is able to decide the "witness" after they've signed (Signer B), which on completion it goes to Signer C.

This is a feature of Docusign, and unless addressed quickly this lacking feature will mean we have no choice but to migrate.

remove signer on the sent document

Ability to change recipients once the doc is sent and signed by another party without necessity to resign it again.

Ability to change recipient's email address once the document is sent.

Signature work around by not using the edit document

Edit wrong email and sent again to destinatary, without cancel the current contract that is working.

Ability for document creator to replace signer or add alternative signer after document has been sent for signatures. Similar to how signatory can forward the document and delegate signing to someone, we would like the ability to do this on their behalf.

For example, a recipient no longer has access to the email and is unable to use document/signature forwarding.

Remove a CC'ed recipient from a sent document so they don't get notifications from comments on the document.

Once a document is submitted for signatures PandaDoc does not allow for adding additional people to the manage recipients on the fly. Meaning once people started to sign the document without marking the document in Edit mode you cannot add someone to a CC role.
When a document is sent there is not a way for the document creator to edit the document without marking the document in edit mode. So for instance if someone signs and suggests that a file is added to the document you cannot do that without it being in edit mode.

The email is not changing any document and should be able to make changes to. This should be as easy as when I received the email telling me the address was not correct clicking and it taking me to correct the change and moving the documents forward.

Also, without having to use document/signature forwarding. For example, if someone is not able to get to their email or is no longer with a company.

creator should be able to add a signer without having to edit the doc and get approval again? Thanks in advance

Yes. Currently, any recipient can forward their signing authority to another person. The DOCUMENT OWNER should also have this ability, for any of the recipients.
Simply enable the owner to be allowed to forward from any recipient to another email (could be a different person, or simply an updated email for that recipient).

Reassign fields on a sent/viewed document (the same feature as was in the Classic Editor)

It would be great if the DOCUMENT CREATOR had the ability to add a CC'd recipient after the document has been sent or the ability to FORWARD the document. To have to recall/resend is a bit cumbersome.

If a signer is added to a document and fields assigned to them, it should be possible to change the signer's name (in case of a misspelling) on the document without removing them and re-adding them.

please make pandadoc 2.0 title of the document editable and to be able to change signers without having to edit the whole document. we request our clients upload multiple documents into our packets and it makes it difficult that we have to edit the entire thing if we need to make any changes. if they've already starting uploading their documents and i have to edit, they lose all their previous uploads.

The ability to add another recipient after a document has been sent without having to put the document into draft status and then be sent out and signed by all parties again.

Once a document is created via the API, it is impossible to alter an email address tied to a recipient. In our use cases, it is completely possible that initial email addresses at the time the document is created, have changed before given recipients get around to signing the document.