Pull requests are required to publish your content to live. A pull request has to be approved and once it is merged, your changes will be live. Read more about it in the Publish Your Changes section.
Anyone in your team who has access to your repository can approve your pull request.
No, you can't. The purpose of having at least 1 approver for a pull request is to have another pair of eyes reviewing your work and making sure that the changes you made are accurate. Having you approve your own pull request will defeat this purpose.
No. the Isomer team will not be able to help you approve your pull request. Pull requests should be done by content owners of the site simply because you are familiar with your content changes. Having an external party to approve for the sake of publishing is the same as approving your own pull request as the external party is not the content owner, therefore is unable to verify the changes are accurate.
Unfortunately no. This is a limitation imposed by Github, and hence we are unable to change this feature.