1) Story quest can be done in all AF. Period. I had to solo tank both of them thanks to a jerk 'AFK'-ing both instances as WAR in full AF.

2) Ifrit is easily done in AF. As PLD, you will be reduced to stun bot anyway. You will want to start collecting DL for Garuda on though. You can also go through AK with AF, but I would recommend getting some DL or two for this as well.