After traveling home for Christmas time, I was finally able to pull up my N. x Velvet, take care of my buggy problem, check the roots for rot, and repot. The darkening of the plant base was most definitely just the plant getting woodier. The dark area was very stiff/hard and is apparently a shade of brown (I am slightly colorblind.) The root system, although surprisingly small, seemed healthy. I didn't see any discoloration or fungus growing. I sprayed the roots and plant with insecticide, and repotted. I used only LFS for the bottom 1/3 of the pot. In the middle I used about equal parts of LFS, Sphagnum Peat Moss, Perlite, and Orchid bark, and then topped it off with more LFS. I got that mix from "Nepenthes Around the Home." The plant looks much better in this medium, and hopefully wont mold on top like the 'northwest' mix did. Here's a picture!