I've been a longtime observer of FFG's 40k line and have noticed a few things that could certainly need tackling in the system. Given that errata comes out sporadically at best, I thought that if there was any time to make a quick list of observations, it'd be before DH 2.0 officially releases (I'm a bit late to the party, unfortunately slow on the draw from when I was still operating under the premise of the v1 Beta).

1. Insanity

Issue: A legacy error passed down from Black Crusade to Only War (due to the former having no Insanity point track), the Shock table remains fundamentally flawed in the DH 2.0 beta. As presented, there is almost no way to accrue Insanity Points without special GM adjudication. Incredibly, an Acolyte is more at risk in gaining Insanity from noncombat situations than in combat with mind-shattering daemonic entities.

Solution: Return the Insanity Point riders from the Shock tables circa DH/RT/DW.

2. Psychic Powers

Issue: Pushing carries heavy risk for comparatively little benefits. Even a psyker starting at maximum Willpower (WP 40), purchasing five advances in WP (to get to WP 65), with a psy-focus (effectively WP 75), only has a 55% chance to successfully manifest a power pushing 2 PR pre-modifiers - which tend to be negative. For a renegade psyker, pushing 4 PR means that same chance is lowered to a horrible 35%. The extra +2/+4 to PR tends to not be worth the failure chance on most if not all powers, and makes pushing mostly useful only for long-term buff powers. Worse yet, it takes away the appeal from being an unsanctioned psyker; elevating the player's risk substantially but rarely coming with any increase in actual power. Removing Fettered and the 'autosucceed on every power where a 91+ isn't rolled' were bold and admirable moves, but we need finetuning.

Solution: Make pushing easier to do and/or more viable. Every PR pushed should probably only impose a -5 on the focus power test at most, not a -10. Adding a Push rider to powers, either specific ones or universally, would also increase the appeal of Pushing under the current system: producing spectacular, dangerous effects that can only be manifested through drinking deeply of the Immaterium...

3. Miscellaneous

Issues: Autocannons and to a lesser extent multi-lasers are too good in the current system, especially compared to heavy bolters. Heavy bolter was rightly nerfed to the reasonable statblock it has today, the same is long overdue for its multiple-shot heavy cousins - or at least to put a hard limit on their mobility/portability compared to the HB.

Snare quality has been too good in practice when it comes to our games. The Helpless condition is almost always tantamount to a death sentence.

The IG background ability is rather underwhelming, mostly because Proven almost never adds much average damage value to weapons.

The Desperado background ability is unclear. Can one insert an Aim action between the Move action and Free Action Standard Attack? Can the pistol Standard Attack be combined with TWW, as the text of Standard Attack (and the flavor of the role) supports?

Solutions: There are several possible (as well as the opinion that some don't need fixing/clarifying), but I've probably soapboxed enough. Thanks to FFG and please discuss if the Emperor moves you!