When the "Former Presidents Act of 1987" was introduced with the aim of controlling costs, the accompanying rhetoric about "wealthy" and "imperial" former presidents didn't go unnoticed in one camp. John H. Taylor, assistant to Richard M. Nixon, wrote a four-page letter to Sen. Lawton Chiles (D-Fla.) pointing out that Nixon has not accepted a speech honorarium since 1953 and keeps a separate budget for his book projects. But the big-ticket item is security, and Taylor writes that "both the Nixons have voluntarily given up their government protection, an annual savings of $3 million."

In fact, Taylor says, Nixon goes about life as usual, albeit with private bodyguards. "He has gone to numerous professional baseball and football games, visited Rockefeller Center at the height of the Christmas rush {and} eaten in fast-food restaurants . . . . " Mondale's Merger . . .

Walter F. Mondale has a Washington presence again, your honor. The Minneapolis firm he joined in September, Dorsey & Whitney, has merged with Busby, Rehm & Leonard here. The two firms will crank up Jan. 1, specializing in international trade, finance and investment. Personnel Dynamics . . .

Alan Woods, a former Defense Department and congressional aide, has been sworn in as head of the Agency for International Development. Woods, most recently a deputy in the Office of the Special Trade Representative, replaces M. Peter McPherson, who has become deputy secretary of the Treasury.

At the swearing-in ceremony, Secretary of State George P. Shultz sounded what's getting to be a common theme in town. Because of budget cuts, Shultz said, "We are going to have less to work with."

The Air Force has lent its top spokesman to the Federal Aviation Administration for the remainder of the Reagan administration. Lt. Col. James C. Jannette, at the Pentagon since 1984, moved into his FAA office this week as assistant administrator for public affairs. Jannette also has been public affairs officer for the Air Force precision flying team, the Thunderbirds.

In New York, Thomas Sheer, head of the FBI field office for the last 14 months, said he is retiring while he is still "marketable" and will become a terrorism consultant next month for Tillinghast, an executive security firm.

"It is true that I have participated in efforts to bring attention to the inequities in federal pay. I have been involved in trying to correct that imbalance, but it has nothing to do with my retirement," Sheer said.Helms on Schools . . .

Here's what Sen. Jesse Helms (R-N.C.) told the Associated Press after casting the only Senate vote against a big spending bill for elementary and secondary schools:

"I am convinced that the problems of education in America can be traced to the time that the federal government began to intrude in what previously had been purely a function and responsibility of state and local government. I am further convinced that the more our schools rely on so-called federal aid, the worse the problems will become."