China Paradise Electronics Retail Ltd. had first half profit slumped 89 percent, reflecting management and cost problems, People’s Daily reported.   China Paradise reached a net profit of 15 million yuan in the first half.   "It's clear the retailer has a lot to do to contain its swelling costs and to improve its management," said the paper quoted Andes Cheng, associate director of Hong Kong-based South China Research Ltd., as saying "Now the focus is on how China Paradise will perform under the Gome umbrella and how long before the two can achieve synergy," said Cheng.