I'd like to start this discussion with a link to https://community.atlassian.com/t5/Jira-questions/Restore-a-deleted-Sprint/qaq-p/674181#M235014 post where I ran into a rather severe problem.
I have been using Jira for MANY years, but without many administrative responsibilities. Recently, I have found myself in more of a administrator or power user role and I encountered a couple of issues.
The issue at hand here is one of both usability and bugs.
(1) above should not occur. It seems to be a caching issue as it happened several times. This is a bug.
(2) also is a bug. The sprint should have been named for the project that I started it in. Again, I suspect a caching (session) issue.
(3) One should NOT ever be allowed to delete or modify data from within a report. Doing so means it is no longer a report. Please remove "Delete Sprint" from the Sprint Report.