uhm kill enemies? well just joking i think the main thing will be to use te enviroment as cover cover is destructable in some way btw
But i heard not in all ways. Part of it may be, but some will be permanate. Also explosions will not cause damaged (craters and the like) in the terrian as this will take too much power from the server/hardware that can be used for other things. As far as interacting with the enviroment, I would like to see NPC Faction-specific defenders in areas that are captured for long enough. Same with some fortifications (these could be distructable?) and some places come to look more like their controlling Faction over time (could be done though the use of fortifications). Example: Orks capture an area from Chaos and manage to hold it for X amount of time. NPC gretchin move in to help as casual defence. More time goes by and those gretchin "dig in" (not really but to explain sudden fortifications lol), adding orky glyps on the building, maybe some trenchs and heaps of rubbish that turn areas that used to be straight into winding areas. This would compound over time and be based off of the size/importance of the area. Small areas would maybe stop at the above discription, whereas a Fortress once destroyed/captured would take longer but would continue to fortify over time, incressing in defences and defenders, untill it is back to full Fortress strength, but now for that new Faction. On a side note this would be great for a Techmarine class to assist with, helping to repair/build things to help speed up that X time untill it gets fortified/healed/renforced. This answers your question about what a player could do to change the battlefield in their favour. But really, as far as we know now, like Savji said, kill enemies and capture/defend areas! Other then that just wait, and hope that some of the good ideas that people on this site and on the Dev team have make it into the game!
More specific? They mentioned there may be some degree of destructible environments so we could see things like bridges you can demolish to funnel heavy armor pushes. It's really early so we don't even know what kind of battlefields we'll be having yet.
IN THE NAME OF THE EMPEROR DESTROY THE LIGHT BULB!!!!!!!!!!!!! SUFFER NOT THE LED TO LIVE!!! PURGE THE NEON!!!
I'd love to spot loose regolith flying everywhere as explosions go off or the ground becoming charred under the blaze of a flamethrower. Perhaps on a larger scale, destructable terrain so the land quickly becomes more and more rugged would be pretty awesome.
Don't see why any of those wouldn't be possible, I hope is some interaction possible on your strike cruisers too.
I'm still under the impression that lighting will be important and that insides and night time will be dark without light sources. Has that changed?
I'm rather hoping that commanders will be able to call down temporary fortifications from orbit (until destroyed). Like, dropping in a bastion, or an aegis, etc.