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That could be Zeus related - the no Zeus zone around players maybe?
There are a few similar air & artillery support scripts around. The fundamental difference with the ALiVE approach is that, like Zeus, they all spawn aircraft off map, conduct the attack run then despawn. One of the core principles of ALiVE is "no magic spawns." You can find any assets on the battlefield, interdict and destroy them, removing them from play. This is important to enable a manoeuvre approach to warfare.
Nope, still on the (long) wish list to develop One Day™
You can stick a Civ Placement module down set to Objectives Only and add a TAOR marker covering those areas, then sync them up to the AI Commander(s). That makes them available as objectives without spawning AI there. It's what the Objectives Only option was made for :)
OPCOM does nothing different. The only variation is on the rarity of the spawns. The profiles are (should be) balanced vs vanilla factions so you get a reasonably combined arms mix depending on the weighting you choose in the module settings. For example, Light Infantry predominantly spawns dismounted inf, but as in reality they rarely operated completely unsupported, so you will still get some HQ units, a few offensive support (MG, AT, Mortars, Sniper groups etc), and maybe a little armour as well. If I recall right, the rarity values for a Light Inf weighting are something like 0.8 for inf groups, 0.5 for support, 0.2 for SF/Sniper/armour/air. Obviously switched around if you select armoured weighting.
The AI Comd Enhancement feature (Ticket #6 on github) was intended to use different groups in a more meaningful way but this never got implemented.
To answer your last question specifically - yes, you could.
Two things here:
1. Clusters of buildings - Civs spawn in the cluster of buildings nearest the player. This is so you can have a higher density of civs in the local area, and not fill up the whole city with civs that the player can't see. Civs in the cluster despawn and the new cluster spawns as you move through town (same way CQB works). At least that should be happening. Have you tried moving through town in a vehicle rather than looking at it from Zeus perspective?
2. Civ placement within the cluster - pretty sure this is as you say, in that the script cycles through available spawn points and places a civ. It's not so much an array of positions but the buildings themselves (and therefore spawn locations) are obviously static. That's initial spawn only though, and civs will move around. It may be possible to inject a little randomisation BUT...if you returned to the cluster 5 minutes after leaving it, all the civs would be in a different place, which might be a bit weird if you're patrolling on foot.
Works off players only.
The limits imposed on ALiVE civs are primarily for performance reasons, both in terms of numbers of AI spawned and the script cycle to minimise overheads. I wonder if it would be possible to use something like Enigma as well - it would provide the numbers, whilst ALiVE provides the funk with the insurgents.