I like the stove by the front of the tent. It will keep the entryway dry and you don’t have to carry the firewood to the back of the tent. To me the only advantage to the right or left side is if you always set your tent up in the same place; you know which way the wind predominately blows put it on the down wind side.
Out the roof or out the wall? Both will have their advantages and disadvantages.
Out the roof is lower maintenance. The stovepipe runs vertically which means less chance of ash building up in the stovepipe and causing a fire. The roof also provides an advantage when it comes to water. Any water that comes in around the pipe is no big deal because the stove dries it instantly. But it has a tendency to put more sparks on the tent top. You can combat this with a good spark arrestor and an extra piece of stovepipe.
Out the wall will allow you to get the sparks further away from the tent (preferably on the down wind side) but requires frequent cleaning to prevent clogging and possible stove pipe fire.
