I'd go Django, even if it's just to prototype the system. If you need to microservice out a django install, just grab all the views and turn each into it's own flask instance with the rest being a collective lib.
Coming from a sysadmin perspective, python apps require slightly less resources than a java apps do. Plus, like someone else said in the thread, it'll be easier to onboard developers at any knowledge level so it's great for beginners and advanced users.
Both. Terminal, and some sort of automation. With Ansible, there's awx and semaphore. I think someone mentioned cronjobs, also systemd-timers. I think kubernetes has a cronjobs feature as well.
With python, it's more about simplifying the entire process (a.k.a. making it pythonic). In my experience, it tends to be a wrapping mechanism around some binary or api so it's hard to pin point "an exact script everyone runs". Some are clean up scripts that clear out caches manually (until a fix can be pushed), others (like this one https://gitlab.com/sunset-crew/nextrelease) wrap git so you don't need to remember all the things associated with pushing a release and/or tag. Ansible, though it's made in python it's kinda it's own langauge, might be a good place to look if you want scripts that are generic enough for everyone to use.
I've written for teams and myself.