Easy killer. I have. I got it right here nicely bound and smelling all nice and new booky, and on my lappy as a PDF. Had it for a while. It's the flame spell bound to my hand, part. Sure I'm over complicating it a bit but who hasn't been guilty of that on these boards, it's a fairly common problem/response for people new to the system. I just was floating it as an idea. Because it's fire that STOPS and moves with my HAND. That seems a bit more complex to me. Does it not to you? Sure I could reduce it down to as simple as shifts of damage in the attack, but should there or should there not be extra shifts involved in discipline, say, for such CONTROL of such heat? Would THAT not be a reasonable question?
The whole thing is a reasonable question. The most basic answer is: Nope. By the rules, there really is nothing more than is needed than writing down a spell name, assigning shifts to it, hitting those shifts with your required roll, and you're done. Nearly everything else is narrative fun and flavor and your justifications for it. There are a few exceptions to this (like turning it into a zone or spray effect, for example, to "Force push" multiple battle droids...er Red Court vampires...and what element you wanted to tie it to for what effects), but by-and-large, the by the book response is what John was saying.
Now, reading what you're wanting, however, what I am seeing is that you are not only asking if there is more, but are in fact wanting more. At least that is the impression I am getting.
If that is the case, you're going to have to house rule it...which is really the butter atop the FATE bread. The game is meant to be house ruled, in fact it begs for it in the form of aspects, and how they interact with your game.
The house ruling could be as simple as just saying "this spell "tethers" to my hand and I call it a lightsaber!" Or it can get far more complex. You could, as John also pointed out, stat it via an Item of Power. You could link it with an aspect inherent to the character ("My Father's lightsaber"). You could stat it as a spell with all sorts of exceptions and unique rules (like getting to use the Weapons skill rather than Discipline for targeting -- which would mean three skills interacting with the spell: Conviction, Discipline, and Weapons; although you could keep it at two if Discipline is modified by Weapons, which would likely be much simpler).
In the end, I think what you really need to be asking at this point is: How are you wanting to see it in your game? By the rules, or more accurate and "faithful" to the source? If it is by the rules, then you need to stop trying to fit the minute details in (like tethering to your hand or "controlling" the heat...that's all part of the spell's controlling roll and subsequent narrative description). If it is more faitherful to the source, then you need to determine just how "accurate" you are wanting to get. Just how potent would a "lightsaber" need to be to cut through steel? (That can, in part, be answered by taking a look at the "Breaking Through Things" application of Might, by the way.) I would also recommend, that if you are going the route of "faithful to the source" the item be done as an Item of Power. That seems to be the most likely candidate to create an actual lightsaber, although it would no longer be a spell, at that point, and rather an actual item...
And of course, none of this addresses its ability to deflect/redirect "blaster" bolts...
