The form in one user task can only be filled by one user, so when the task is sent to a team, only one member can actually perform the task.  If you need multiple users to perform on the form, you should have multiple user tasks. But the number of approvers can not be dynamic. But if all the approvers are fixed  but just each time the approvers are dynamic based on the user selection, then you can use inclusive gateway to route the tasks based on selection.

For signature, if it is not set to read-only, it won't display the signature signed in previous steps. So you current design of putting them in a table will make the signature not able to show if user 1 signed the signature and submit then user 2 view it.  A possible solution is add separate signature field for each approver and  use separate form for each user task: the fields on each form actually are the same but just their status of read-only are different: for example, in the form for user 1, only the signature for him is editable, other signatures are set to read-only.