That rod you've chosen is built specifically for float fishing. Meaning it's better suited for jigs, bait, beads, etc. under a bobber. Not that it won't work for drift fishing or spinners but it's a really good float fishing rod. Float fishing is usually done from the bank more than out of a boat where other techniques are more effective such as side drifting and bobber-doggin.
As for the Fire line, it is used as the mainline. It's just one of many lines manufacturered for float fishing. The idea for float fishing is so that the line will float, not sink like monofilament line does, to effectively float fish. Your presentation (i.e. below the float) would be with a monofilament leader.