1000 point critiques

Airborne
Succubus (Haywire grenade, Archite Glaive) 100
Blasterborn x5 (4 blasters) venom with splinter cannon 180
Warriors x10 (1 splinter cannon) dissie raider with nightshield and splinter racks 180
Ravager with dark lances 125
Wyches x9 dissie raider with nightshield 170
Reavers x6 (2 heat lance, 2 cluster caltrops) 146
Scourge x5 (4 haywire blasters) 120
1001

Kabal
Archon (haywire grenade, Agonizer) 90
Incubi x6 dissie raider 175
Blasterborn x5 (4 blasters) venom with splinter cannon 180
Warriors x10 (1 splinter cannon) dissie raider with splinter racks 135
Warriors x5 venom with splinter cannon 105
Reavers x3 (heat lance, cluster caltrops) 73
Reavers x3 (heat lance, cluster caltrops) 73
Razorwing with monoscythe missiles 130
991

Cult
Succubus (armour of misery, haywire grenades, archite glaive) 115
Blasterborn x5 (4 blasters) venom with splinter cannon 180
Warriors x5 venom with splinter cannon 105
Hekatrix/ Wyches x8 (haywire grenade, phantasm grenade launcher) dissie raider with torment grenades 200
Reavers x6 (2 heat lance, 2 cluster caltrop) 146
Scourge x5 (4 haywire blasters) 120
Dark Lance Ravager 125
991

All three the HQ is riding the raider that makes the most sense for them.
Feel free to critique them, the more construction I get, the better.  Unfortunately, we are  at 1000 games for the time being.

Not sure the "Coven" one can be called a coven without any coven units

In general lists look like a lot of fun but here are what I would consider:

1) Archon wants an agoniser. Agonisers are king, far better then power swords for example!
2) Hellions really struggle in the new codex, they just don't perform well enough really
3) Phantasm Grenade launchers are 90% useless as soulfright doesn't work on marines and it no longer confers grenades to things
4) Shooting weapons on the reavers is alright at lower games where you might want to have them, but Reavers will almost always be jinking so shooting can be pretty ineffective.
5) enhanced aethersails are great if you are using the raider to deliver wyches or whatever, gives you that extra distance to hide or maneuver to allow an assault turn 2
6) There is no point to taking a hekatrix unless you give her an agoniser. If the wyches have to take a leadership they will probably all be dead anyway!

I'd second everything Grub has said, adding also that the sybarite is largely useless, and you almost certainly want to be taking dark lances on the raiders. The splinter cannon on the warrior squad is ok, but just be aware its range is restricted if the vehicle moves, and it actually makes the squad less efficient in terms of wounds per point, and though it can (and usually does) increase the potential maximum damage of the unit, if the raider has moved and its target is more than 18" away, it actually reduces the number of shots you can fire.

Sweet, changes so far then

Airborne: Sybarite, Hekatrix, and hellions gone, Dlance Ravager in its place. Should still have enough general dakka.

Kabal: Power sword and Sybarite gone, Agonizer in it's place, will be adding aether sails to that raider.

Cult: name changed! That hekatrix stays for the theme right now. That army will be playing Tau/Guard, and between the Armor of Misery Fear/leadership penalty, i felt between assaults the soul fright had some decent synergy.

Is there any particular reason why I should arm raiders with d. lances? I feel that they should be jinking more often than not, and though weaker, more shots with the dissie would be preferable. Opinions?

Thank you so far!

Mainly because the more dark lances you can fit in, the better. Dark Lances are your turn 1 anti tank to let the rest of your army do its job. Realistically in your original list the scourges were the only unit likely to be able to damage vehicles on turn 1. Now, with the ravager and if you bring 2 dark lances on raiders you've got 5 lances and 4 haywire blasters, but crucially they can target 4 different vehicles so should you happen to face a rhino based army (or similar) then you can cripple them early on so that your anti infantry firepower is doing maximum damage as early as possible.

Blasterborn are great, but they're not going to be in range on turn 1 whereas dark lance raiders are, and you get the benefit of being able to hide them from fire should you go second.