I found some more I could do on my own, though now I'll probably take a breather so that others can provide ideas like I asked for previously:
v0.23
Added item textures for: turbine blades (un-colored from the Railcraft Turbine Blade), turbines (un-colored from the Railcraft Turbine Disk)
Updated item textures for: buzzsaw tool heads (my original texture came out a bit darker than other tool heads, so I made it lighter)
Added item textures for: fine wires (based on the Mariculture Golden Thread texture)
Added item textures for: soldering irons (based on the Forestry Soldering Iron)
Added aspect texture for: Strontio (by vertically flipping the Thaumcraft Cognitio texture - the default GregTech texture for it seems to be a horizontally flipped Cognitio, but I figured that would be too hard to see the difference with Sphax textures, so I went with a vertical flip instead)
Added attempts at machine textures for: Electromagnetic Separator, Fluid Solidifier, Fluid Heater, Fluid Extractor, Brewery (original textures I made in GIMP, so they probably aren't that good)
Added machine textures for: Large Turbines (scaled up and cut apart from the gas turbine side texture)
Added block textures for: cable insulation (based on the IC2 Rubber Block texture)
Added machine textures for: Fermenter (based on the IC2 Fermenter textures)
Added block texture for: Drain (extracted from the GT 2.82a textures for MC 1.4.7)
512x:
https://drive.google.com/file/d/0B5WJmT ... sp=sharing
256x:
https://drive.google.com/file/d/0B5WJmT ... sp=sharing
128x:
https://drive.google.com/file/d/0B5WJmT ... sp=sharing
64x:
https://drive.google.com/file/d/0B5WJmT ... sp=sharing
32x:
https://drive.google.com/file/d/0B5WJmT ... sp=sharing