Regarding crashes related to Vulkan executable:

I was playing, until yesterday, with Radeon 10.8.1 and never experienced a single issue. Updated to 10.9.2 and I have my first crash with a Vulkan error at the battle outside the Druid Grove gate. Played a bunch since but no additional crashes.

The quest where Wyll wants the goblin knocked out so he can question him has an outcome, despite doing everything correctly (you also see the approval go up), where Wyll will say that he wanted him alive and not dead even tho he interrogated and got the answers he needed. I reloaded the sequence several times and tried different methods. Funnily, knocking him down with the knockdown action breaks the quest since the NPC will remain on the ground and the dialog can't proceed.. So currently the only way is to have him surrender after taking sufficient damage.

When the PC is sneaking the NPC cone of vision does not collide with z-axis, so it's possible for NPC to detect through a hill or other similar structure if your character is on the same z-level. Also this happens when you are on another level and clearly out of sight but still get stealth checked.