Gabe,
Take a voltmeter and measure the voltage at the cigarette socket at idle and at, say, 2500RPM, and report back here.
That won't rule in or out the alternator, but would give you an idea whether there's a problem with the electrical system or not. But I would doubt the electrical system causing your cutting out issue; if it did you'd loose all power (including the lights on the dash, and radio, etc.) instead of the engine just starting to stall out.
Lasher,
Could you describe your shifting problem in more detail?
BTW, there's another thread where another member says a 95 Impreza MAF is a good substitute for our MAF's.
VK