I always draw on the pipe when tamping otherwise it can snuff the pipe out if you are just hitting it with the tamper. Dottle I think more has to do with where the hole is on your pipe. IF its not all the way at the bottom then you will always have dottle.
I am a noob at pipes but started tamping recently after the first relight when it becomes difficult to keep the bowl lit. The next relight appears to be a charm if that makes any sense.
Sorry I've missed this thread for a couple of days!
You can accomplish the same goal of the angled tamper, effectively remedying the "tobacco doesn't burn around the edges" phenomenon by using a smaller diameter tamper ala the Czech Tool, and simply push the ash from the edges of the burning tobacco into a cone. You just kindof angle the head of the tamper inwards toward the center of the bow, and push down, lightly scraping the ash/unburned baccy away from the bowl walls. This is done very subtly, and you don't actually want to scrape the cake or walls of your pipe heavily, but just softly to form something that looks like the burning cone at the end of a cigar. It is rather like tending a fire, where you push the cooler perimeter towards the center.
That isn't to say I' never tamp straight down, because that is also an integral part of keeping a bowl burning. But if you are dealing with unburned baccy around the edges of the bowl, try this. Also, a good relight never hurts! Gentle puff, a lit match, and you're back to an evenly lit bowl.