Compression Test Results

From my '72 107 M116 - 170, 160, 160, 160, 135, 150, 160, 150

OK, I'm not a mechanic but I'd like to know a little bit about this before I send it back to the shop, if I have to. #5 looks real low and #6&8 look low. What does the low compression mean to the engine and could this be causing the following: Car starts fine, idles a little ruff while cold. I start down the street which gets the car to 3rd gear (auto). I've got a stop light there and everytime I have to stop the car blows dark/bluish smoke and studders like it's missing until I get it to crusing speed, say 40mph. After it warms up it's fine.