On a side note your dagger points toward the ground when your arm is relaxed at your side. Do people ever do it the opposite so that the dagger points toward the ground when they raise their arm or is the way you did it "standard"?
I've always felt that tattoos need to follow some basic rules of gravity....so a dagger pointing upward (when arm is relaxed) tends to look unnatural, just like faces should always point towards the center of body, not away from it (towards the back)
not an official "rule of tattooing" but just tends to flow better visually
I did see a tattoo a long time ago where some guy had lettering on his forearm's underside (forgot what it said but it was not nice words) done upside down, as you mention, so that when his arms were raised they read rightside up. It was one of those phrases where basically if he's beating the crap out of you, the tattoo is readable and makes sense.