Call Lightning is good enough considering its duration. Don't forget that at lvl 5 you actually get 5x3d6 (and 5x3d10 if outside and it is raining or stormy weather). 15d6 at lvl 5 is pretty good. Later its damage becomes weak, but so does spells like Fireball at high levels.
Still better to take Spell Focus Conjuration and Augment Summoning than Point Blank Shot and Precise Shot.
Not good enough for me, same with fireball.
Call lightning competes with communal delay poison and communal resist energy for spell slots, while fireball is a waste of space compared to stinking cloud, slow or haste. At lower levels a druid with a longbow (or rather sling now) and buffs can get more out of his spellbook than the few lightning bolts, subject to reflex save & evasion. And at higher levels there is sirocco. Regarding the feats, at level 5 your one spontaneus summon lasts 5 rounds, which is not long enough to make use of augment summoning. Later levels summons are only good as doorstoppers. If spontaneous summoning would work like memorized spells, the situation would be different, but as it is, clerics with animate dead and monster tactician inquisitors make better summoners.
I like my druid, but frankly, all the lower level offensive spells were a disappointment and the shapeshifting was buggy, which is why I switched him to a bow.