No, 29 is not too cold. And I don;t think it would take "twice as long" at 34 that 29. Probably almost no difference. Just get it as ocld as you can without freezing. BTW, most people also lager way longer than is necesssary. A 1.050 lager only needs 2-4 weeks tops. A doppelbock might need a few months, but lower gravity lagers are good to go after only a few weeks - at 29 or 34.