@Rasmikant Bal Thank you for reaching out to Microsoft Q&A.
#1 Local Tab you see in Diagnostic Logs is a new feature to store data in APIM local for Self-Hosted Gateway version. Unfortunately, there is no documentation yet and our product team is currently working on to publish the docs. Sorry about the lack of documentation and requesting you to follow Product updates on the latest updates.
#2 No, currently admin can edit all APIs, Products in APIM instance and I see similar feedback in the feedback forum
Under Review. Please feel free to upvote this feature. Alternatively, you can add email addresses for notifications such as Subscription requests, New Subscriptions etc. (not customizable) so that additional users will receive notifications (refer Configure notifications in the portal).
I hope this helps with your questions and let me know if you have any.