Note that Tuffskull has been working on an urban combat 'bolt-on' for DRM's Seeds of War rules, you might find that interesting.
http://hobbybrush.com/articles/suburbanpdf/ FWIW, he seems most focused on building destruction, which seems different from your approach. Perhaps this is why he's terming it "suburban warfare."
My general comment:
The temptation in dealing with a hive world is to design from the bottom up -- "how should buildings work?" "I've got ramps and flyways, how do I deal with them?" "What about multi-(flowerpot) level buildings? do they have elevators?" "How do I deal with elevators."
But I would advocate designing from top down:
"How should a hive environment shape battalion/regimental-level combat?"
"Is a hive-fight like the historical cityfights that we've seen?" (e.g. Stalingrad, Ortona, Arnhem or Hue, etc. all the way up through Mogadishu, Grozny, Fallujah, and Gaza)
"How can I capture the essence of that fighting by tweaking the Epic:A engine?"
"What would be the differences between Stalingrad and a hive city? How can I capture those differences by tweaking 'Epic:A/cityfight.'?
I'm not sure exactly how I'd answer these last questions, --- nor am I sure whether the below is 'top down' or 'middle out."
Still, one 'first cut' at dealing with Urban combat might be that it's characterized by extremely sharp distinctions between open and closed terrain. At the one hand, it's very friendly to PBI (poor bloody infantry) while at the other, extremely unfriendly -- life sucks (and it's very short) if you're in the street, life is pretty good if you're in a building (that is, aside from the rats, the stench, and the starvation). This dynamic might perhaps be only more distinct in the context of a hive city.
Another point: force to space ratios can become astronomical in cities -- in general, on the Eastern Front, a division or so was expected to cover (what?) ten miles of frontage or so. If I recall correctly, the Russians and Germans poured about five divisions into the Red Barricades factory on the volga river -- a big factory to be sure, but not likely to be more than a mile square.
And then there's the question of the characteristics of the hives themselves: just how restrictive are these environments? How and where are vehicles useful? Are we talking about an environment where a Space Marine in his suit run into trouble getting through doors, seeing behind himself, etc (think tunnels of cu chi)?
) so any comments would be greatly appreciated.
