It was panic stations at the arts endowment last week. The presidentially appointed national council members--many of them famous, such as writer Toni Morrison and ballet impressario Robert Joffrey--flew in for their quarterly meeting, and the 'crats were smiling and scampering. As for the new Reagan appointees, most paranoia focused on Samuel Lipman, concert pianist, music critic for Commentary and author of the Heritage Foundation report that charged the endowment is more concerned "with politically calculated goals of social policy than with the arts." As it turned out, however, Lipman, a short, intense man, asked some probing questions about money and philosophy and let it go at that. "What I would like to do is provide a kind of intellectual consideration of the issues that lie behind setting up programs," he said. "Everybody was surprised," said one NEA official. "Clearly he's a very intelligent person who knew what he was talking about." Friday night, council members mixed at NEA chairman Francis S.M. Hodsoll's $750,000 McLean manse. The new members were upbeat: "My initial impression is the NEA people are far more sincere and competent than I had dared expect," said Raymond J. Learsy, a businessman and William F. Buckley Jr.'s brother-in-law. Novelist Allen Drury said he is looking forward to "doing something for the arts in an essentially nonpartisan way." Actor Robert Stack said he is "happy that this government, which is associated in most people's minds as a bureaucracy, is treating such an esoteric area with respect and love. It's wonderful, really.