-- The retirement of liberal Representative Cardiss Collins (D-Ill.) has left corporate lobbyists grief-stricken. Not that the ranking Democrat on the House Government Reform & Oversight Committee is a friend of business. But if Republicans lose control of the House next year--a prospect raised by the Democrat's stronger-than-expected showing in state races on Nov. 7--business' worst fears could come true. Its dreaded foe, Representative Henry A. Waxman (D-Calif.), would chair the committee, which has broad powers to investigate abuses by government contractors. "We're all horrified," shudders one lobbyist, who says it's sure to spur the denizens of Gucci Gulch to pull out their checkbooks anew for Hill Republicans.