Can I ask what you disliked about the writing around Brennan? I feel like I was never impressed with that plot point, but couldn't really place why.
Brennan Jones was a beautifully dimpled flash bang plot grenade.
His TLK with some rando nurse while under a sleeping curse (if he is to be believed) bent the established rules of TLKs until there were stress fractures in the whole idea of it. They never explained why he was a fugitive (unless I’ve conveniently blacked it out at this point), and what was so horrible he would abandon that cute fucking kid of his and his future mass-murdering brother (dear lord, don’t get me started on that) to a life of servitude and abuse. Nope, he essentially got rewarded for his crappy parenting.
The writers shoehorned in that unnecessary scenario between Brennan and Killian between scenes with the EQ from season 2 that worked just fine without this little sojourn into patricide just so they could use this line repeatedly:
(Obviously a better man than you even on his worst day, fucker! )
Because of the Jones Patricide Incident™, we were also subjected to more unnecessary Evil Queen scenery chewing when she sent Killian off to kill his Daddy as a test to see if he could kill her mommy, too. That act had 0 bearing on his attempt to kill a powerful woman with magic (dude was an opportunistic pirate and would have killed her for the right reasons without being tested, lbr) and had even less emotional fallout. The whole thing was, in my mind, pointless.
It also gave us Liam the Petulant (aka Liam 2.0) who has had no seemingly lasting impact on Killian. Sure, they are cordial now, but I doubt Liam 2.0 will be over for Thanksgiving. And even though Nemo (my love!) is attached to Liam The-Less-Mass-Murdery story-wise, they could have written him into Hook’s past without dragging another kid named after a dead relative.
TL;DR: If you took Brennan Jones out of the story, everything would have continued to work just fine and made
OUAT sense. His character, in the flesh, was pointless if not pretty.
In conclusion, The Brennan Jones storyline makes me ragey in its epic pointlessness. It pissed me off enough I wrote fic to fix it.