No.
While things like changing the description of someone casting magic missile is neat and all (and that was a rather neat refluff of the spell earlier in the thread!), IMO it leads to the setting losing internal consistency and cohesion.
There are things that exist in the world; magic missile is one of them. When someone uses it, the characters should be able to recognize it, if arcana is one of the things they know about, because that's how things work. While it might appear slightly differently, there is no way to mistake the effect for another one. If you start doing this willy-nilly, it completely - IMO - nixes the players' ability to plan and identify threats. They have no idea what's going to be thrown at them, so the world becomes - from their view - chaotic and disorganized.
As a corollary to this, I will make new stuff up whole-cloth if what I want doesn't exist. But I will not try to pretend and/or trick the players into thinking it's something else, and if the characters have the means to recognize it, I will give them the chance to do so.
But I will not take something and redress it to make it "neater." I work with the tools I'm given and/or make, and work within those constraints. In my mind, it makes for a far more interesting experience, because the players know that I won't change things up just to make things interesting; they can rely on the idea that if something looks like a duck and quacks like a duck, it is - in all likelihood - just a duck.
