I will preface this with the fact that summoner is not my main, though it is a close third after PLD and SCH. I enjoy summoner quite a bit and I see under-performing mechanics as a challenge and like to try to make them work.

Currently I feel Radiant Shield is a wasted ability, as I'm sure many do, since Ifrit doesn't put out enough enmity to make use of it at all. Maybe make it more of an AOE(trash packs)/support egi. Allow Radiant Shield to be cast on another party member, and when on Sic, would allow it to be cast on whoever takes damage when it's off cooldown, like say, the tank.

Another QOL change for ifrit that might give it more of a niche is possibly making his Burning Strike hit several enemies in front of him as well. Ifrit would shine as trash pack clearing egi. Garuda would continue to be good on bosses.

I tried searching the forum to see if they had been brought up before and didn't see anything so I figured I would throw my 2 cents out there.