Hm… There are some errors in your config files, although that’s not necessarily the source of problem you were asking about. Still, it would be prudent to clean them up, either way. The new fly config validate --strict will show various warnings that flyctl doesn’t mention otherwise.
Also, type = "requests" is generally better for HTTP—unless you’re using WebSockets, or the like.
This part unfortunately isn’t possible, unless you implement your own downscaling, etc. The min_machines_running knob only affects the primary_region.
Hope this helps a little!