You're better off with the haswell over the ivy bridge because of the newer instruction sets that x264 utilizes. (I can't find the changelogs)
-Lots of disks. Especially if it's important stuff. 3x 1tb drives over 1x 3tb drive.
-Motherboard, don't care.
-case, doesn't matter.
-sound card, depends. Do you need ASIO (low latency recording/playback)? Higher fidelity audio?
-Ram, enough. 8/16/32, more just means you can be running non productive stuff while working on stuff.
-GPU, OpenCL/Cuda only for effects and decoding. Encoding quality with GPU accelerated encoders aren't as good as non-accelearted ones.
As for tf2. Nvidia's newer driver causes flashing DX9.