nooby...it is entirely likely you have a defective unit...there have been a few that get too hot and need to be replaced.
However, that's not the most likely scenario. You have a ton of variables...temp, fan/draw speed, and the herb you are putting in there to name a few. You are doing the right thing by backing down on the temp until it gets right. The first thing I would do is try some different weed and see what happens, as they all seem to like a little variance.
Unfortunately, that smokey smell can be hard to get rid of...just check out your old bong. You may still be tasting the smoke smell from your first burnt batch. See if you can identify which parts of your system need cleaning. I would start with the glass pieces closest to the herb, like the bowl and elbow. If they sent you two of them, use the other bowl and the elbow from the whip (assuming you started with the bag) and see if that helps with the smell.