With the insight park killing I wonder if we are reading too much into it? Maybe the victim was thrown into the hedge and stabbed with the ritual dagger and the magic bit is just related to the ritual dagger? This would make the cause of death more consistent (strength based anchor, bashed, hung) with one use of breath weapon.
The mortician's notes say "Felson Felgrim, was found entangled in a hedge and died from slashing damage. The mortician notes the slashes are indicative of thorns rather than a dagger. On your visit to Insight Park, the druid believed a spellcaster used nature itself to kill the victim." so unfortunately it does look as though the dagger isn't implicated in the actual cause of death here. Unless some of the slashes were with a dagger and the thorns were used to disguise that fact, perhaps?
Unfortunately, I'm being no more decisive this morning than I was last night. I'm very aware that if Rourke is indeed leaving the city, this might be our last chance to catch him. But it's also possible that we missed our chance by not going to Saint Sollars Way yesterday and we'd be wasting our time following him (and Mrs Leventide) and would be better following up on a different lead. And indeed that they're not leaving the city at all but are going to hide out at Riverveins or with the Guild so we'll find them later. Argh! Can't decide.
"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"