Why double speeds? Why not just pretend the time interval for the turn halved?
As for weapons ranges, you would run on number 200, not 255 - anything above 200 you can leave as it is. The only problem I see with 25m hex is really just the burst radius.
Re source code, I also believe only Don and Andy are allowed to tinker with it. Being a non-programmer, I am glad the tentacles of C spaghetti stays where it is and does not endanger bystanders