Solution n°3 : HEAL
This one doesnt work at the moment as the chocobo doesnt seem to be able to heal our summon. It could be viable if fixed : tanking with carby/titan (or even Ifrit) while chocobo is healing.
+ you're DD, no heal should be needed.
+ Can even tank stronger mob, by adding your heals/regen to the chocobo's one. Best BIG TANK option (low dps) ?
- Have to watch your aggro.

Solution n°4 : Hybrids
Like said before, Hybrid could be nice too and might end to be the best option (stun/heal/tank). Endless farm too ?

Everything is open. Thoughts ?