I check the PA forums from time to time for updates and how the mod community grows. My intention is to eventually develop a gameplay mod for PA that changes the economy and units, provided PA still gets mod support to allow people to play mods online against one another. (My aspiration is to develop a PA mod that is more focused on finite resources, where you extract and utilize matter to produce units and energy to enable production/transformation & commanders are degraded to typical units. ) But, as far as I can tell, as good as all mod discussions at the moment are UI related, unit names or planet models/textures, and perhaps one balance mod. I have not seen anyone go into detail about adding/removing units, change the techtrees/dependabilities, abilities of units, or even allow for different economy structures. (Another unrelated question is whether bullets/lasers have collision detection, as this would allow one to make units that are large in size to soak up damage like shields.)
Sounds like you have some great ideas! Mods like that won't be possible until Uber releases the server (which will happen when they bring PA out of gamma/early access). Once that happens we'll probably have tons of mods for new units and total conversions. (I'd like to make a Stargate total conversion mod if I can get the time and find someone with 3D modeling skills.)
There is proper simulated physics, so yes. For more info there are different projectile types too; like ballistic (I assume affected by gravity), direct (lasers), seeking (homing missiles), staged (who knows what this means, bombers weapons are staged but then so is the stingray aa gun). The nanoloathes are not simulated afaik, so a combat fabber could theoretically reclaim something behind an obstacle.
