@GENERALZOOLPretty sure DICE confirmed there will be no singleplayer campaign because they wanted to focus on multiplayer, as it is DICE's strong suit.
There hasn't been said anything about a potential "Scripting Mode" or anything similar to that so far.
For your last question, we know that the following modes will be available to play:
"Multiplayer – AI soldiers are used for server-filling capabilities, ensuring your matches remain full, no matter your location.
Co-Op – Allows you to play together with friends, against AI soldiers.
Solo – If you wish to perfect your skills for multiplayer, you can even play alone against AI soldiers."
So Co-Op and Solo are essentially the PVE modes you asked for, which will be available.
You can read more about it here: https://answers.ea.com/t5/Battlefield-Announcements/Battlefield-Briefing-Welcome-to-2042/m-p/10415599#M1
