S. Africa getting cold feet on Namibia freedom?

Is South Africa getting cold feet about giving up control of Namibia (South-West Africa)?

Just as there is new optimism about a settlement, Foreign Affairs Minister Roelof F. Botha has reignited the guessing game over whether Pretoria really wants to settle - on any terms.

On a visit to Namibia, Mr. Botha raised questions about whether ''free and fair election is possible.'' He says he has evidence showing SWAPO (South-West Africa People's Organization) leader Sam Nujoma ordered the assassination of political leaders in the territory. SWAPO, a black nationalist group, is fighting South African troops for control of Namibia.

This is not a new charge. SWAPO has in the past claimed responsibility for killing tribal leaders for collaborating with the territory's government.

However, Mr. Botha's new charges are sweeping. He said Mr. Nujoma issued orders to kill all influential leaders of the territory and to carry out sabotage.

SWAPO's activity, he said, makes withdrawal of Cuban troops from Angola ''much more urgent.'' He said Aug. 15 is the target date for a cease-fire in the region's bush war. South Africa has already set a condition that Cubans must withdraw before Namibian elections.