Hello!
Thanks for the report, I can confirm about the edit bug in the timeline, it should serialize like the other actions when editing.
Honestly the whole timeline section is quite old, and might need a revamp/sunset, maybe its better/easier to use the branching tree which can have attached scripts and better ux…
About the folder, yes, Also if you have a document (not a folder) selected the new file/folder will be a sibling to that.