After receiving the Presidential Medal of Freedom here yesterday, Frank Sinatra went to Hoboken, N.J., to receive an honorary degree from his hometown college, the Stevens Institute of Technology. The singer had vowed never to perform again in New Jersey after a feud last year with a state official who called him an "obnoxious bully" in connection with an illegally dealt blackjack game in Atlantic City. Yesterday, though, he told the graduates, "It's more fun being here than at the White House because there nobody raised a fuss" . . .

While actor Mickey Rooney was in Washington last fall appearing in "Sugar Babies," he spent much of his free time at Laurel Race Course. Now that the musical has brought him to Baltimore, Rooney can often be found watching the ponies at Pimlico . . .

Princess Diana was never in any danger, and in fact was unaware of what was going on, when British police yesterday arrested a man in a crowd awaiting her visit who was carrying a toy pistol and a cigarette lighter shaped like a hand grenade. The 41-year-old man with the toys is apparently a local eccentric, but then, one never knows . . .

California authorities have recovered 18 paintings by surrealist artist Salvador Dali valued at more than $600,000. The paintings had been stolen last July from the Signature of Fine Art Gallery in Newport Beach . . .

Former Washington senator Warren Magnuson's right foot was amputated yesterday because of a circulation problem, a Veterans Administration hospital spokesman in Seattle said. Magnuson is 80 . . .

The Washington Opera's opening performance of Gian Carlo Menotti's operas "The Medium" and "The Telephone," which were smash hits here last season, opened in Israel Sunday to rave reviews and a seven-minute standing ovation. American Ambassador to Israel Samuel Lewis hosted a reception following the performance that was attended by Israeli President Chaim Herzog; Jerusalem Mayor Teddy Kolleck and Abraham Harmon, president of the Hebrew University in Jerusalem. Lewis said, "When I return to Washington to serve on the faculty at Johns Hopkins University, the first thing I plan to do is subscribe to the Washington Opera" . . .