For your second question, according to How to associate the “.exe” extension to be opened with Mono?, you need an
Apparently, when using Finder's GUI, only
.app files (application bundles) can be selected.
If that's true for Python scripts as well, then my answer at that question might help, with for Step 5:
echo "$f" with
python32 UliPad.py "$f"
So, in short, create an Automator "application" to run the following Shell script:
if [ $# -eq 0 ]
# No parameters passed; just run it without any files:
# Run an instance for each file:
for f in "$@"
$PYTHON $ULIPAD "$f"
...or maybe you can pass multiple files to
UliPad.py in one go:
$PYTHON $ULIPAD "$@"
As for your first question: you should be able to use the same Automator "application" to just start UliPad without opening any file (if indeed you then just need to run it without any parameters, like I assumed above).