I don't post here that often... I mostly just lurk... but I couldn't ignore this topic. You sound exactly like me. I've been experiencing these exact same symptoms since about August of last year. I know exactly how you feel, and I, too, felt at one point that I was gradually losing my sanity...
Pranks at my school were always lame. This year the seniors whipping creamed CLASS OF 08 all over the school, put some ratty, old couch in the middle of the quad, random chairs around it, an old TV set across from it, hung a tarp from two trees, set a box filled with water balloons by the TV...
Irrational. I'll get freaked out if anything's in my room, crawling around on the ground or floor, but I can look at a picture just fine, even though any arachnid is kind of gross. I have a problem with killing them, though, so I either just move them with cup to paper and put them outside or...
Humans CAN teleport from point A to B on Earth by using Xen as a slingshot.
Combine CANNOT teleport from point A to B on Earth, and can only teleport from one universe to another.
The Combine teleport you see Mossman use in Nova Prospekt was made by giving Eli's research to the Combine...
I remember reading an interview where someone from Valve said the episode format hadn't worked for them. I don't remember where I found it, but I think it was from here.