I really don't think scripting will take the game in the right direction because it would worsen all the problems that you mentioned... If that check is removed and all it takes to wage all out war is to fire up a script (I'm sure you can replace "independent worlds" with "worlds belonging to sover...

If I was inactive for a couple days I wouldn't be particularly surprised if someone swooped in and trashed my empire. That's fine. It's just not my thing. If you had been defending with starfrigates I probably would have kept clear of your empire entirely and concentrated on building more citadels ...

Hello! Two years ago, I founded Monjardin Hegemony and quickly conquered almost double the worlds of the next largest empire. That empire got crippled by an alliance of much older empires while I was asleep. I did a lot of damage to one of the attackers, but soon abdicated as attrition was withering...