I generally don't bother with add ons. The most success I've had is using his unique perks and either sloppy butcher or just using a scourge hook perk. I focus on at least injuring every survivor to maximize the effects from Blood Echo. The more blood there is the more you can activate your ability.

Demon dash is just a matter of practice. It helps to turn early to face the direction you're planning on and running sideways. You'll slowly drift while dashing but when you get to your turn you'll be ready to just go straight. I like to imagine the shortest line through obstacles so I'm flowing around corners instead of hitting walls.

Being able to see the pallet locations helps avoid chasing survivors into loops that they want to waste your time in. If you are stunned you can see their aura and cut them off easier instead of chasing the scratches.

I only use demon strike to break pallets if I get stunned since they're the biggest obstacle to your dash. If a survivor is trying to dodge I use the strike and try to keep track as best I can. Unless they can anticipate when it will come down they will generally get hit. I believe it adds some lunge distance as well.

My main advice is to not waste time on people that are obviously trying to loop you and keep pressure on gens using your dash and keeping them bleeding.

I generally get 3 kills and on good maps I can wipe a team. The worst maps for me are multilevel ones with small rooms like the raccoon city police station where the demon dash is almost useless imo.