DEALINGS between the Clinton family and the Whitewater land development company are far from the only business-firm/politician-relationship case now under scrutiny in Washington. A number of complicated ethics cases are roiling political waters, though in no instance has any misdeed or impropriety been proven:
* Commerce Secretary Ron Brown is under fire from GOP members of Congress for his receipt of $400,000 - a year after assuming his present post - from a firm he did little work for, and invested no money in.
Mr. Brown helped found the company, First International Communications Corporation, while a private law partner in Washington. Thereafter he gave firm head Nolanda Hill general advice, but little else. First International paid him over $400,000 for his stake in 1994.
Furthermore, virtually the only source of revenue for First International has been payments on a promissory note from a broadcasting firm that has defaulted on government-backed loans, costing taxpayers $40 million. Mr. Brown says he knew nothing of this inter-company relationship and that his involvement with and payment from First International is typical of high-level business deals.
* Senate minority leader Tom Daschle is under scrutiny for his efforts to help an air charter company, run by a friend, which was involved in a fatal crash last year in Minot, N.D.
The company, B&L Aviation of Rapid City, S.D., felt for years that it was being hounded by inspectors from the US Forest Service, who had some jurisdiction over their operations.
B&L's owner, Murt Bellew, was a longtime associate of Mr. Daschle. He enlisted the senator's help in a two-year attempt to strip the Forest Service of all authority to inspect air-charter firms.
The Federal Aviation Administration, whose second in command happens to be Daschle's wife, aided this effort against a fellow agency it may have felt was intruding on its turf.
A B&L aircraft carrying three government doctors crashed last Feb. 24, with pilot error the probable cause. One FAA official now says that documents related to Senator Daschle and his involvement with B&L have been destroyed.
Daschle says he was simply trying to promote an obvious method of streamlining government operations.
* House Speaker Newt Gingrich, dogged by Democratic complaints about his much-publicized book deal, now faces the revelation that his wife was given a job to help promote an Israeli free-trade zone - after Mr. Gingrich publicly supported the idea to top Israeli officials.
Marianne Gingrich was hired to the post last fall by American investors who have been trying to get the Israeli government to designate such a zone for years.
Mr. Gingrich says there is no conflict inherent in his wife's business dealings and that he has been a well-known supporter of free trade and free-trade zones for many years.