Tips to Start as Psyker
If you have line of sight, left mouse button is your go-to for head popping.
I used to use right mouse button (in the beta) for hounds but I basically never use right mouse button anymore.
You can spam left mouse button until you find your target, the tallest enemies are the elites.
You can pop-tart, so crouch, stand up, grab a target, crouch and head pop under cover (this is more for level 3,4,5 difficulty (because snipers are a real pain)).
Get used to doing stuff while dodging backwards. Get used to doing stuff while side dodging.
Get used to walking into a doorway, grabbing a target and side dodge left / right (out of line of sight). It doesn’t matter what you grab; don’t get OCD over it.
You are looking for a “Force Sword” as your primary. Figure out what staff you like around level 10.
Your secondary is important.
For beginner guns, I really like the submachine gun (called: “Shredder Autopistol” which was the Preacher’s weapon in the beta test), because usually as a Psyker, you are heavily pressured at close range. The SMG is designed as a point blank weapon.
It’s a huge pain if I can’t get a smg in level 0-5.
Segue the SMG into either an “Auto Gun” or if you can’t find either of those, the Infantry Lasgun is a semi-auto, high power, high ammo count, with holo sights. You need high ammo count weapons (350 ammo), so as not to burden other classes like Veteran Sharpshooter (that specializes in guns and needs the ammo).
Try and use your primary to melee, to conserve ammo but don’t hesitate to pull out your secondary.
Jedi Master level skills: try jumping up to grab head poppers.