I use Hate/Resolve contextually and based on the importance of the scene but also on how the players are doing. The "marsh dweller" example above is a relevant one as my players are new and this adventure has not only a shadow test for entering the flooded chamber but also likely when facing the fell wraith later. As such "machinegunning" players with the strike fear ability by all marsh dwellers seemed like overkill but also as not conducive to good drama and a good game.
As such I (did the same with 1E) use hate points for dramatic effect or to add drama to a scene that matters a lot. This has served me well. I also tell players I am using a point and what fell ability it is. I will also lean on player distinctive features (used to be traits) like enemy-lore if relevant. In that sense a player facing a group of undead with the DF Enemy-lore: undead, gets a 1d boon on his or her Lore or Battle roll to know that this enemy has some fell abilities or weaknesses. This brings the enemies alive for players I find.
This is a good approach! Sensible and keeps the game fun rather than burying the players under hate.
Although their Machine Gunning potential has gone down a bit post FAQ/errata as they're now "Thing of Terror" instead of having "Strike Fear".
I like your use of the appropriate Calling to feed the PCs information. I'm a bit more generous here, giving the information for free and just requiring the roll for extra info:
"the Loremaster should rarely require a player to make a LORE roll for information regarding their own character’s Culture, Background, or the area they originally came from." (p64) Particularly as the FAQ replaces "Background" with "Calling".
I agree its is a great way to bring foes alive and to make use of the Callings. I'll often let "Shadow-lore" be broad and then the Specific "Enemy Lore" give more precision, with both getting extra info via rolls.