Ok, forget the thought of making something comparable to such High-end developed games. This I say because of the questions you ask.
My guess: it is more than capable if you care to do some optimization yourselves. Can you show me a RTS game with more than 4k poly for each model?
Personally my tests with 5k character models, each with 5 different parts and 56 bones.
Comparison:
the upcoming Total War Shogun 2 has
52 bones per character vs 56.
some troops will have as many as 1000 polygons per unit vs I tested with 5k polygon.
My guess, my 2048x2048 textures were also higher than Shogun2 will have, I guess they use max 1024x1024 at close.
I got 78 Characters on screen without too much optimization. included were 48x 12k houses. and 40x 1k poly trees. Every object had 3-4 textures applied, specular,normal,color and detail.
How receptive is the engine to implementation of new systems (i.e. Construction arrays, specified GUI operations, inclusion of custom harvestable resources, etc)?
Construction arrays
Well, first I have to ask, what is this array, because from what I see you say harvestable resources is a core engine feature. do you mean constructors of classes or do you mean in-game buildings? even though I bet both are possible. and I am certain the last one is possible.
specified GUI operations
Implement your own GUI if absolutely needed.
custom harvestable resources -> this is gameplay feature and got nothing to do with the engine. and yes this is easy, I made such a feature from pieces of the bloody massacre code and simplifed and modified it.
LUA, Phyton can indeed be implemented or any scripting language, its up to you on how advanced you want to make it.
on the C4 Engine only RTS game I've seen from it is the bloody tide
http://bloodtide.demalus.com/index.php?p...ct=general
it got a basic tutorial I guess on the wiki but the tutorial only goes through what every basic RPG game usually contains.
EG: unit/character/enemy selection in other word
Unit movement = click & move.
Camera is certainly possible. As I think every game engine which is generic in game types allows you to make a RTS camera.
UnrealEngine is not catered towards RTS or MMO so that rules the question out, certainly possible if you had the source code to the pro super expensive UnrealEngine and not the indie UDK one but yeah 100x 5-10k poly characters all active AI will get laggy.
Not to be against C4, but it's very pro Nvidia based meaning you will make it unplayable for ATI/AMD users, they might have to play at low, and Nvidia can play with older video cards at high. from most projects I've seen and tested they are also every single one unstable eg: sudden FPS drop at simple scene, objects falling through terrain/objects.