Hakeem I respect your understanding of themes, but we have a very limited card pool to deal with.
The theoretical 3 CMC or less Izzet deck suffers from a problem of threat density. No matter how hugely they are pumped, relying on 4 kiln fiends as your sole threats is simply not enough. One shock will shut you down. If you throw down a kiln fiend, your opponent will be forced to do the following:
A) Use removal on it;
B) Leave 2 or more blockers behind at all times.
Even a fairly control-oriented deck with kiln fiends should be able to outrace players that are running more conventional decklists. Think of the impact that kiln fiends have on the board not only directly, but by shaping your opponent's perception of your own game plan.
Guttersnipe and Talrand use a different mechanic, but fundamentally they are threats that synergize extremely well with instants and sorceries. Kiln fiend is simply the most dangerous 2 drop in the format and can protect your other threats by acting as a removal magnet, at the very worst.
Are there thematically "purer" kiln fiend builds out there? Why yes, but not really in the Duels 2015 card pool. There are no cards on the power level of goblin guide available to smash face in early. I need to spend some more time playtesting, but what I have said above is a defense of my admittedly inelegant decklist.
Good to see you over here, HenWen, you're one of my favorite posters.
I have built my Izzet decklist without Kiln Fiend because of the reasons you state;
Shock can shut you down and you run out of resources if you don't draw it on time. My point is that Kiln Fiend is an aggressive card and should be backed up by cards that enable an aggressive strategy. Jamming the Fiend into a deck and trying to "combo off" will win you games, but it isn't consistent and it's easy to play around. Kiln Fiend also doesn't synergize well with counterspells (because it's aggressive).
Guttersnipe and Talrand, however, aren't aggressive cards on their own; they reward you for disrupting your opponent and protecting your board position. They both synergize extremely well with counterspells (because they're defensive). Sure Talrand's Drake tokens are aggressive, but the process of creating them is defensive in nature.
The Kiln Fiend deck is probably a viable Izzet deck, but I don't think it will have the consistency and reliability of my control build. It will be swingy, capable of blowouts, but also very capable of being blown out.
Anyway, what I'm saying is that Guttersnipe and Talrand synergize really well in a defensive Izzet control deck. I've built it, I've tested it, and it works.