Lets give a little bit better feedback in this thread please.
I would use Synergy on Brackenspore if you're going to play Demo, I've played it on a few kills but mostly Destro due to the Havoc SB opportunities. With that being said a couple more things I found:
Damage on Mind Fungus seems a bit low, I would recommend putting Corruptions on them if your guild isn't killing the ones that spawn no where the stacking group. You should also make sure you are using HoG properly, feels a bit low, maybe you let it sit on 2 stacks? Think of it like Conflagrate, every second it's at 2 stacks it's a DPS loss. Effective way to use it is use one charge, cast 2-3 spells dependent on Haste then clip the 2nd stack for a 2 stack 6 second HoG on the target.
Spore Shooter damage seems also a bit low, make sure you are applying Corruption to them and HoG if they are stacked up since the Fury gain is greater than putting it on Brackenspore, also make sure you are keeping Doom / Corruption up on both the Fungal add and the boss, lot of Fury loss there that you had. If the Spore Shooters are stacked up you could try to get the killing blow on them with Chaos Wave to gain some of that fury back. Also dependent on how your guild deals with the blue mushrooms, try to save a Demonbolt cycle for it, as well as an Imp Swarm. I always use Imp Swarm glyph because I like the synergy it has with the Demonbolt Demo playstyle, I get mine down to 80 seconds when standing in a blue mushroom, and I believe 22 seconds on Demonbolt.
Rotation looks good, Demo is all about fine tuning, if you make a mistake with Fury generation it is very costly and noticeable, just keep practicing I'm sure you'll get it, if you have anymore questions don't be shy to post and I or all the other talent Warlocks here on this forum will get to it ASAP.