No, in order to watch insta stories, you need to have an Instagram account. The stories are exclusive to the Instagram platform, and they are designed to be viewed by the users within the app who are following the respective accounts.
Sadly, it's not possible. Instagram stories are meant for Instagram users. They are shared among the followers of an account within the Instagram app. If you don't have an account, you won't have access to the feed where the stories are displayed. Also, the privacy settings of the accounts that post stories are set within the Instagram environment, and without an account, you can't be recognized as a follower or viewer.
No, unfortunately. Instagram stories are an integral part of the Instagram ecosystem. They are created by Instagram users for their followers, and to access and view these stories, you must be part of the Instagram community, which means having an account. Without an account, you won't be able to see any of the stories, whether they are from public or private accounts.