Today's selection of letters from readers really covers the waterfront.

For feds who constantly hear how much better their retirement system is than anything in private industry, there is a letter from a college professor. He says that compared to his federal counterparts, he's got it made.

Another Monday Morning Quarterback hopes government workers can mount a boycott that will send the Reagan administration a message. At the same time, the writer fears that the boycott may flop because feds are either apathetic or don't know how to fight back.

In another letter, a 20-year employe says this administration has changed him from a dedicated civil servant into a time-server who enjoys seeing the government get the shaft.

This is what people are writing:

"I am a $42,500 college professor about to retire after 30 years of teaching.

"With Social Security and my teachers annuity, I will get something like $32,000 in retirement, or about 75 percent of my final salary. As I understand it a federal worker at age 55 with 30 years gets about 56 percent of his high three-year salary average.

"A federal worker could only do as well as I will by purchasing an extra annuity. He'd also have to do it the hard way -- using after-tax dollars rather than tax-deferred dollars, as in my plan.

"Moreover professors in good colleges don't have to pay tuition for their children. I have a brother who retired after 38 years on combined Social Security at age 65 and a private company pension at 65 percent of his final salary.

"All in all I am not impressed by the pension of a 30-year civil servant . . . .

"Advocates of good federal-military pensions are on the defensive, but those benefits are really rather stingy compared to good retirement provisions in the private sector." Better Off in the Private Sector.

"Smoking, radio playing, children -- none properly belong in the office.

"The office is intended to be a work place and all of the above are major distractions from that purpose. The problem is once one giveth, it is difficult to taketh away." K.D.K., Alexandria.

"It warmed my heart to read your column about the National Treasury Employees Union picketing establishments owned by J. Peter Grace, who headed the Grace Commission. That commission has proposed a number of major changes in federal pay, pensions and benefits to save money. I hope all federal unions cooperate and coordinate a boycott of Grace operations, at least in the Washington area.

"My only concern is that an ineffective campaign will lose us what little respect we have with President Reagan and his cronies.

"Federal employes are partly to blame for our present situation. We haven't utilized what political and economic tools we legally have at our disposal. We have been called on to bite the bullet, give generously to charity and buy savings bonds, which we have done. The reward for our dedication and acts of charity has been to have our benefits continually cut back, attempted salary freezes, and job security threatened.

"I wish workers would decide what measures can be taken against the administration within the bounds of the law. My hope is that we can make life as miserable for those people who have dumped us for the past four years as they have made it miserable for us." M.K., Gaithersburg.