Im not getting all the summoner hate.Yes there's a lot going on with the job but its quite a strong job currently which is likely to scale better later into the expansion.
It's high skill high reward situation but incredibly fun to play.it may need a bit more potency tweaks but currently its hard to say.If SE not careful the job will get overbuffed in the right hands.
As for soloing non dungeon monsters and fates etc the job can burst down fate bosses quite fast and a decent leveled chocobo will keep you alive.Just try to avoid fates that spam unavoidable poison.