Unfortunately, you won't be able to be as efficient as a scholar cause you don't have the same toolkit.

In Nocturnal Sec, you have one HoT but you need to use Collective Unconscious that you may need for damage mitigation more than the HoT it gives (while scholar can use Sacred Soil and Whispering Dawn).
But it's up to you to know when to use it. The HoT is really powerful and it's always good to use Celestial Opposition to increase the duration.

Also, always use Disable for Tank Buster or strong aoe damages. It's a short CD and can be stack with Virus.

Shields have basically more potency than scholar, due to the fact that he has no pet to help. For this point, it won't be a problem.
Maybe using Bole on the group or the tank could be a way to deal more damages mitigation, but...do we really choose an astrologian on this purpose?(I mean using dps buff is better)
Again,it's up to you.