Should i keep my Fahrenheit in?
Also, This deck has no creature control, should i ad a fire bolt or rain of fir to help with that?
I would use the second deck stan posted, except I would probably drop out two Pillars and add one more Immolation and one more Photon. If you want to keep Fahrenheit, you could trade a Golem for it (I probably would).
change out a card for fire shield[i know its a rush deck but still] that will help a lot
I disagree. Your only goal here is to kill the other person. You should be ending the game in 5-7 turns. In that case, the fire shield would only be effective if you play it in your first 2-3 turns (in order to have time to kill an average creature), and at that point you need your fire quantum to be playing creatures. The shield would only slow you down.
Same logic goes for creature control.
[edit: Just reread the OP and noticed you wanted to farm AI5 and FGs. First, you're not going to be able to farm FGs with a completely unupped deck. Second, I'm not sure about AI5. Given that they have 200 HP, they have more time to get set up, so I'm not sure rush decks fare as well. You can try, but if they can stall or heal, you may deck out or be killed.]