That would be a pretty awesome project. Not sure how you'd go about getting midi values direct from it though, perhaps you could stick in a cv/midi converter, or an arduino? That would allow the led feedback.
Aftertouch might be complicated, because I would assume they just use momentary switches.
The strum is just a momentary as well.
The neck wiggle is just a mercury switch, so the only really continuous control you have there is the whammy, I'm not sure of the resolution of it.
Heres what I would do to
Firstly get an arduino(you could get a bluetooth one if you wanted it wireless)
the whammy bar should be easy as i assume its just a potentiometer with a spring system to bring it back flat. the output of this could head straight to the arduino.
For the led buttons, you could set the leds next to the buttons, keeping them intact(im not sure what you are using the leds for, so location may be more important)
keeping the original switching intact would probably be a good idea, and you could use piezo elements to get a velocity reading, while note length would be determined by the original switching.
again, this could all go into the arduino.
This same technique could be used for the strum control.
And you could replace the mercury switch with an accelerometer.
I haven't really looked inside my controls so I'm just making all my assumptions on their current workings from what I've read.
Or, you could find a cheap small midi enabled keyboard.
Used the cc's for the whammy, and the inner workings of the keys for your switching.
But i've no idea how you'd go about the leds with this one.