1) I don't feed live to any of my snakes currently, but when I do, I have 12'' hemostats on hand. With large feeders, after the strike and coil, I like to give the rat something to chew on other than my snake.. and that ends up being the tips of the hemostats.
2) Pre-killing is easy. Cervical dislocation is a technique I particularly like for separating the spinal column and instantly killing your feeder. I pin the head gently with a pencil at the edge of a table. Firmly grab the BASE of the tail. Pull the tail straight out away from the head, as if you were trying to break a rubber band by stretching it too far. Don't jerk, just be firm and quick. There may be videos on youtube. I like this better than CO2, it's faster and (IMO) more humane to the feeder. However, it may not be as easy for YOU to perform mentally. A similar technique is used to dispatch large rabbits farmed for their meat, and I've successfully used cervical dislocation easily on rats as large as ~200g, so it can even be done with large feeders.