1) The other ipks contain various modules that you may or may not use, depending on your needs. A full blown python installation is something like 40 MB, so I think the python_2.4.1 ipk is only the core.
2) Make sure the readline ipks are installed. This means both the regular readline ipk and something like python-readline.
3) I haven't tried idle itself, but for Tk applications, you need tcl/tk installed, in addition to python-tkinter.
4) Not sure on #4. I use books :-)
This is all from memory, so the filenames might vary a bit. All of the above work for me, so you should be able to get what you want. Good luck.
Mike