Stocks opened mixed today in slow trading, influenced by new uncertainty about the outlook for inflation, interest rates and the dollar. The Dow Jones average of 30 industrials was up 4.62 points to 2,079.30 by 10 a.m. EST. Among broader indicators, the New York Stock Exchange composite index of all listed issues rose 0.34 to 150.97. The American Stock Exchange market-value index rose 0.66 to 291.85. Gaining and declining issues were nearly even on the NYSE, with 415 up, 414 down and 495 unchanged. Volume totaled 14.96 million shares after the first 30 minutes of trading. Wall Street strategists were divided about the market's direction. Many said prices were due to strengthen given the pessimism that has pervaded for awhile, making some stocks attractive. Others said too many economic uncertainties were making stocks risky. An Organization of Petroleum Exporting Countries price-boosting accord could raise the inflation rate, the dollar has been facing heavy selling pressure and talk has increased about a possible Federal Reserve move to tighten interest rates. On Friday the Dow Jones industrial average fell 17.60 points to 2,074.68, finishing the week with a net gain of 12.27. Declining issues outnumbered advances by about 3 to 2 on the NYSE, with 513 up, 778 down and 521 unchanged. Big Board volume came to 72.09 million shares, down from 112.01 million Wednesday and the lightest total since a 48.86 million-share day on Dec. 26, 1986.