OK the first u shall change is your resi stone in neck, its better to put ele cloak lvl 4+ in or royal cloak (expensive, all skils +1).
I see on your passive tree that you spend 2 points int the first 2 skill bars down.
You don't need them --> Power Surge, Nimbleness, Intellect, Mind Boost, Endurance stage 1 only. Same for Force Claw, Wingover, Strong Mind, Iron Scale only stage 1.
Purgatory and Distribute on stage 5 for what ? Only good when you without any evolution to slayer, orbiter or summoner --> when u change the buff dissapears. Don't skill them, let them be on stage 0.
Sacred One --> stage 1
For more crit search for good crit weapons ( Xenon and Karon with minimum 5 % crit for 140% dmg, DMG, AR and if you are lucky All ele attack + stun/ or one of them, but they are also not cheap in the AH )
And u can look for Barom rings that gives 4% crit for 140% taken dmg, if you wish glori shuta or blode + glori kark --> increase your crit dmg to mobs.
And what steph33 said, yes ranger buffs helps alot.
But 3700 Crit is good at your lvl rage to this mobs. At lvl 100+ u only can raise up your crit to 12 ~ 15k crit with the right equipment, lens/lens+ on maybe up to 16~18k crit.
But GL with leveling your summoner up to 120 its always nice to see that some ppl play this class during other classes are to strong atm