Your main issues in your proposed list ideas are;
1. No viable anti-tank. Transports especially are still a thing, especially anything that's a skimmer and/or comes at a steep discount like what Codex Marines/
DA's/
SW's can spam through their super detachments.
IoM armies, Orks & Chaos in general will also still put some decent armoured support on the table, especially Orks who love to run Battlewagons for example.
2. Nothing is really that scary in combat...
Sure if enough Bloodletters all hit home at once, but you've ignored most of the really big threats the army is capable of throwing down.
Honestly, I'd look to something built around;
Slaughtercult:
- Chaos Lord w/Jugger,
SoC, Kor'lath - 'Axe of Becomes a Bloodthirster'
- 2-3x 8 Bloodletters
- 5x Possessed + Rhino
- 2x 8 Cultists
- 1-2 units of 2-3 Chaos Spawn
Gorepack:
- 2x 3 Bikers w/2 Meltaguns + Combi-Melta (I know you said you hate bikes, but seriously, this is your best source of real anti-tank!)
- 8-10 Flesh Hounds (Gorepack Hounds gain
HoW hits, which makes an already great unit even better.)
You can add in more Hound units, which isn't a terrible idea by any means - Gorepack Hounds are the best damn unit in the whole codex!
War Engines:
- Soul Grinders
- Fiends. (Forge w/Hades cannons if you want more anti-tank, otherwise Maulers for bum rushing the enemy)
Lord of Slaughter:
- Bloodthirster of Insensate Rage
Allied Codex: Daemons detachment:
- Be'lakor
- 11x Pink Horrors of Tzeentch (gives Be'lakor +2WC's on top of his 3 +
D6, helping to ensure that even on a bad roll, you still have enough charges to throw out Invis)
Things to keep in mind:
1. The Chaos Lord can join a unit of Flesh Hounds, which will also have the added bonus of conferring the unit's Scout special rule to your hyper-killy Lord! On the flip side, the Lord brings some much needed, at-initiative ap2 + the occasional Instant Death attack.
When he (inevitably) dies, his axe then turns him into a Bloodthirster of Unfettered Fury. (ie: the basic one)
As for not being able to apotheosis him onto a 'Thirster? Well, you have two Cultist Champions who are still characters, and thus, viable targets for such an honoured sacrifice!
2. Gorepacks
are the army. Especially against more competitive lists, you pretty much have to resign yourself to the fact that the Gorepack (and thus Bikers) are a necessary evil for a Khornate force...
Basic
CSM's cost far too much, especially in a Khornekin force where you have to pay for 8 base AND get the relevant
MoK cost added on top of an already awful unit. Hence, Bikers are your main source of special weapons, since they combine speed, cost effectiveness, and maximise the number of special weapons they can take at basic unit size. (basically, they do everything right that basic Chaos Marine do horribly wrong!)
Flesh Hounds within a Gorepack pretty much have no equal.
3. Bloodletters are actually really bad at their one job!
Sad but true, the Bloodletters aren't really showing up for their killing potential, but rather, because they're so damn cheap and give Tithes pts much more efficiently than anything else bar Cultists.
When it comes to killing power, you're looking at the likes of Chaos Lords on Juggers, Flesh Hounds, 'Thirsters, Soul Grinders/multiple Maulerfiends hitting the same unit, Flesh Hounds, Chaos Spawn... did I mention about the Flesh Hounds!?
Another allied option to try out, is to take the new Cyclopia Cabal from the updated Black Legion supplement... Don't bother with any Marks on the Sorcs (it only makes them worse actually!), slap them all on bikes, and then join them either to an existing bike/Hound/Spawn unit, or else ally in some
MoN Bikers from the
CSM codex. (T6 ablative shields + Power fist Champ)
You can roll their powers each 1 Telepathy (and default to Psy Shriek), then 2 Biomancy powers, hoping for Endurance and at least one Iron Arm... Makes a great little Deathstar, though is definitely pts heavy.
)