To answer your question: no a para is not only for daily life skills. The school should provide him 1:1 with the areas he needs it for. My son's IEP is for his reading and math. He has an aide for both classes as well as visual aides but the rest of his classes he does not have an aide. My son is high functioning and verbal. I agree that you have to make a case for the 1:1 and definitely ask for a PWN. Also keep any and all communication in writing. I print everything out that I receive from the school regarding my son and his educational needs.
An aide, para, etc. is not defined in IDEA. Nor is "life skills" actually.
The main tenet of IDEA and IEPs is I--individualized. If your son has needs identified that would warrant a 1:1, then you're to have to make the case for it, ask, then ask for a PWN.