There are a few topics regarding Nuke's modifications.
More in: search.php?keywords=super+icbm
If you need more detailed help with specific questions, I would recommend to create a new topic in this subforum: viewforum.php?f=54 in order to keep the current topic clean and just UP1.5 focused.
However, if you use the "Normal" version of UP1.5, you will need to backup your changes, because they get automatically overwritten after every minor update.
Also, I don't think it will be possible to increase the visual explosion effect. It then requires changing much more files, which are less understandable.