Visibility: I have heard several negative reports on Fog-X. Too bad, because Rain-X is good stuff! I wouldn't bother with the Rain-X wiper blades, though. I believe that stuff has to go onto a clean windshield to make any difference.
Rear wiper delete: Look at the junkyards for an HF hatch. Or any hatch (hopefully the right color!) without a wiper. It'll be lighter, too!
Alignment: There are things you can to to change the alignment specs. In particular, it's very easy to add positive camber to the rear wheels by putting shims (or washers) between the upper lateral arm mount and the car's body. Make sure to use longer bolts, though, because you really don't want those falling out.... There is evidently some adjustment in the rear toe link as well, even without swapping or adding parts.
Brakes: Try to find the early HF aluminum drums. Good luck in the search, because you won't be the only one looking. The drum setup should be lighter than disks, so keep your drums unless you want to swap for ease of maintenance or for looks. (It's not like hypermilers really use their brakes, right?
)
If your pedal slowly sinks to the floor while the car is stopped, the problem is with the master cylinder itself, not the booster or the vacuum system.
Fluids: As Christ says, the light is not the most reliable indicator. Borrow a known-good mechanical gauge and see what it can tell you. Low pressure at idle on a well-worn engine isn't that unusual, depending on how low it is. And on how low your idle RPM is.
-soD