Looking at all of the tutorials and tools, I think the one aspect that is lacking is ship editing.
Currently it is the hardest/most tedious thing to edit and perfect. In addition to having to look up the weapon number and search for the parameter you want to change/add (ie acceleration, armor etc.), you have to meticulously adjust the weapon and thruster positions, which involves constantly going into a mission in FC to test the current position.
So what I am currently crafting right now is an editor for ships, programming entirely in python with a GUI interface and released as a windows executable (since the current versions of FC only work on Windows).
The main feature will be a 3D display of the fighter/capship with highlights on what you are editing. Weapons would of course end up being points (probably spherical), but if it is possible, I would add in display of thruster flames for fining ability.
Once fighters are fully editable, I plan to add in turret editing for capships, which will provide users with the ability to more easily fine-tune their turret matrices.
Essentially this will be very similar to WCPedit with easier to edit turret and hardpoint tools.
So before you start work, let's coordinate. Ship xml has some new fields in 1.7.
Also 1.7 has changed how you refer to weapons. In 1.7, you can refer to weapons by name, not by number.
Also, I'd wait on capships. Since they're a bit useless now, turrets don't fire yet.
The ship display idea is very cool, it is hard to place the mount points. But let's think of other approaches first.
The way most people would probably do it is:
Create the .obj mesh of the ship.
Open up the .obj in a 3d editor of your choice.
Place weapons and engines from within the 3d editor.
Copy the locations from the 3d editor into XML.
Also, I've already taken a stab at this in Java, although it is quite outdated, and was written for an old version of flight commander. You're welcome to the source if you like. It edits some xml fields, no 3d.
Anyway, I can put up an early version of 1.7 for you if you're interested, to avoid getting outdated.