you can’t duplicate scenes.
you create a scene either in SmartThings or in ihost.
I have simple, typically local scenes in ihost.
complex ones in smartthings. in smartthings I mainly create scenes for matter devices.
No. The pro runs Android and has a browser. What you could however do is ask your iHost to watch for if either of the physical buttons are pressed and then do something when it is. You would just need to remember what the buttons do or set up a notification to your phone what you have done.
I have never used this other system but my guess is that someone has already made an Node Red palette for it. Then you could just install the Node Red docker image on the iHost and only create 1 automation anywhere.