alright here's some advices i find the most crucial. all the effects were made with planes with textures, always think what interaction could or must be organic to the player, know your toolbox well and if you understand it well enough only then you can search for more tools, read books, also experience with other engines might help.
in other words i used tonnes of extensions, binary exe by JIC for extended API. the game doesn't use any third party shaders
also the method used for adjusting the shovel's orientation can't be used for things like bullet holes since the issue would be the same. sad but true - engine doesn't support decals. u ether know programming well to make an illusion of stuff like this or just forget about it and move on, like i did. Sure the spectacle would be much more interesting and fun if there were bullet holes and blood pounds but hey, at least you still can make some stuff with particles, which is still fun kinda, and also these stuff doesn't determine the game