You probably do need more calories than someone in a sedentary job, however, an active job doesn't replace cardio.
Here's how you figure out how many extra (if any) calories you may need: www.sparkpeople.com/community/ask_the_expe
Cardio provides benefits beyond simply calorie burn; if your heart rate isn't getting into the cardio range (which I assure you, it isn't while pacing) then you're not getting the heart-healthy benefits it provides. It also doesn't sound like you're doing any strength training, which is a critical part of any good program. Without it, much of your weight loss can come from muscle... which reduces metabolism. REgular strength training will also boost metabolism overall and help you burn MORE calories doing just about everything.