Narrowing RFC authorizations

I have seen the following objects thats directly related to the RFC auths

1.S_RFC ( Auth Check for RFC acess)

2.S_RFCACL (Auth check for RFC user )

3.S_TABU_RFC ( Client comaprison & Copy -Data export withRFC)

Now the question :

What else is needed ? The answer we need to determinewhat else is doen by the RFC user ..etc I understand!!

Thanks