Lets make things clear: i love the game so far, and got addicted from the start, even it being in alpha. So the following comments are not rants, but rather constructive criticism. Also i will not talk about item balance, since i know you are on it already.
I think the feel of being an inquisitor is off. first, i dont think the assassin class should not look like an assassin. More frail and more agile, sure. But not with the armors of the Officio Assassinorum. Maybe some adaptations, but it currently feels too much like i am playing an assassin than an inquisitor. The adrenaline mechanic works, making the assassin feel different from the Crusader, but the look feels 'out of context'.
Tou are more than an assassin, you are an inquisitor.
I find that the weapon selections are kind of meh for an inquisitor. Why would an inquisitor, wielding the power to annihilate whole planets, wield a lasgun/autogun? Maybe at low level, but they should be totally outclassed the further up you go. Maybe it gives 2 less options, but it could be compensated with different types of plasmagun as an example. Maybe the Mars pattern has 1 or 2 different skills out of the 4, or something like that.
The should be powerful combos for wielding both a melee and a pistol. They are the most common weapon setup for inquisitors, yet it feels sub par by a big margin compared to other weapons.
I hope to see the psycannon for the Psyker. would be amazing.
Here is my biggest gripe. It feels not much worth it and kind of break the lore imho. Itemization with stats (and color coding) gives a feel that the items are magical. Which is far from the lore. Here is my suggestion:
Items would be blank, no stats. the quality of the item gives a number of addon slots. Like white = 1 slot, blue = 2 slots, etc...
Then you have addons that you can put in the item. They are the stats. They are what customize your item. be it Extra Plating (more armor), Silencer (reduce aggro range from attacks) or a visor (increasing accuracy).
That gives you a much more 'close to lore' feel, and an interesting crafting system. Maybe an armor type can have multiple patterns that gives a basic adjustment, but not more than that.
So you have:
1. Craft your base item (Pattern and # of slots get unlocked with level / research)
2. Craft your addons (Bonus capped with level, better ones get unlocked with level / research / reverse engineering)
3. You could extract an addon from a drop, and use it or reverse engineer it.
4. You could maybe upgrade the item / addon to make it better? Maybe add a slot, reroll bonus from addon.
5. You could maybe extract the visor from a lasgun you found, just to place it on your plasmagun?
The possibilities are endless, and can be lots of fun. Making crafting items not limited in usefulness. And sticking with the lore!
Could even do set bonus, like if you put this type of addon with this other type, you get another thing.
I would like to see some incentives to some maps vs others. It takes more time to do a purge than an assassination. It should show in the rewards, both xp/items. Also, if there could be bonus loot/xps from clearing maps and such. So that if you want to do it, even if its an assassination, then you can and be rewarded for it.
It would be nice if there would be no 'money'. More an Influence (rep to unlock better gear) and Requisition (quantifying your 'weight' in the ordos, akin to money). See the Dark Heresy system, or the Deathwatch one (RPG).