altering the current objects is simple, but illegal in some countries due to copyright laws. You can edit the current buildings vehicles players objects etc, textures can be changed, the 3di models can be molded and changed. You just have to find the right tool to do it and also live outside a country that inforces copyright laws.
otherwise everyone would be enjoying my version of what the df2 engine should have looked like
I dream of the day DF2 is given as open source lol