Playing with the big boys - Trickster (Nightshade/Shaman) in ultimate difficulty

Continuing where I left off from -
Elite end game - skill selection. Turning a noob into a pro

I managed to kill off the act 7 boss who was nice enough to drop this axe:

I went back and completed the ‘key/challenge’ dungeons - ancient grove and tomb of the heretic.
They didn’t pose a challenge.

I can complete crucible medium difficulty to around level 39.
I’m guessing that perhaps some tweaks are in order.

Heading into ultimate difficulty, what problems does one face?
I’m assuming more emphasis on defense is required?

Suggestions welcomed. Thank-you