1 pointHi, You can create a point group to contain all points before the Clip SOP and then invert this group:
1 pointwhat exactly do you need to know? just make selection by @name directly in Material SOP. Or make groups from the @name and then use those as a separator, if that's more comfortable for you.
1 pointThat is just for opening a hipfile from the python interface, be it a Hython console, python node, or executing a script with Hython from the command line. Once you have the scene loaded, as in the examples on that page, you can access all of the objects within it to process. I would suspect you aren't going to be needing to do this unless you are automating some pipeline stuff that needs to affect many files in succession and process them.