Bloodcrushers: Since you are not slowed by terrain, use it. Rush into combat using terrain as cover, after all once in a fight, Laz cannons can't hit you. Charging through terrain does make your I1 (for sure now with FAQ out), so hop out into the open, survive overwatch and kill them, tr and roll high for consolidate and get back into cover.
Bloodletters: I always Deepstrike them. I use them as my linebreaker and late game back field objective grabbers. if they happen to kill something, all the better. I also use them with the Horn to help pull in other units. Banner is nice to negate scatter on those other units.
Berzerkers: Back field protection or put them in another Rhino and just move them forward and disembark into terrain. You have pistols to weaken a unit after hopping out. Counter attack if they charge you, rage and furious charge if you get to charge. Champion should look at using either an Axe of Khorne or Chain axe. Challenges are extra blood tithes win or lose, good blood tithe management is key to a win.
Posessed: Same as Berzerkers, hop around charge those guys on foot. FYI: Mutations last full game turn, not just the player's. If they are stuck in melee top of turn 2 and bottom of turn 2, they could have two Mutations from the list on them.
Terminators, My favorite build:
Chaos Terminators - Icon of Wrath
2x Combi- Melta, Power Axe
Combi- Flamer, Power Maul
Combi- Melta, Power Sword
Deepstriker unit Melta to kill a bothersome vehicle, flamer for later before charging. Icon gives Furious Charge, and may re-roll charge. Melee weapons are mixed so your Sword has a chance of killing at initiative the challenger, Maul for a heaver hit, Axes AP2 at I1.
Used in the formation Terminators and Bloodcrushers get the +1 attack each if outnumbered.
Models not in so far:
Chaos Spawn: 32 point Blood Tithes. They run fast and can be very good in a Maelstrom game grabbing objectives. T5 makes them hard to hurt, but no base save. Put them into the Blood Host and they could have +1 attack and Feel No pain. They also make good Juggerlord (chaos lord on a Juggernaught) body guards since they have the same T5 as him and can move just as fast.
Flesh Hounds: Scouting 2wounds each that move 12" per turn makes them targets, but gives time for your slower units to catch up and not get targeted. Any back field vehicle that has back armor 10 should fear these. In the formation they gain Hammer of wrath and preferred enemy (Psycker).
Chaos Bikes: Another source of Melta. In the formation Shred on the Hammer of Wrath.
A lot of my base knowledge came from https://1d4chan.org/wiki/Warhammer_40,000/Tactics/Khorne_Daemonkin%287E%29
and playing it for a few months now.