41236T 6PP T 6PK 2K - Works on anything who isn't heavy. (NH 75+9, HiC 96+9)
41236T 9P T 6PK 2K - Works on everyone. (NH 66+9, HiC 84+9)
Don't need other combos.
(Optional stun/CH) 214P T 6PK 2K - Works on everyone. (NH 56+9, HiC 82+9 (add a 9P before airthrow))
Stun/CH 9K T 6PK 2K - Works on lightweight and lighter. (43+9 (not including the hits that stunned or if 9K CH))
Obviously, if you get to threshold, you can do more stuff, but I don't play stun game with Rachel. Quick stun launch is good enough for me. If you do want to play stun game, make sure you can react to their critical holds so you can 41236T and laugh at them.
After the air throw, instead of 6PK or 3PP, use 6PPK (second hit whiffs?). I haven't tested it fully, but it seems to be a pseudo force tech, at least. (Might not work on everyone, I haven't tested- works on Ayane.)
I think it will come in handy if 2K doesn't work out for some reason, or if 2K magic gets patched out.
4PPP, 66P (CB), 3PPP+KT (i.e. just go into it directly). 103 damage, works on heavies (tested on Rachel).
If that doesn't get them to hold mid punch nothing will.
You might already know this, but the Viper Twist airthrow says "to foe in the air" in the command list but actually works on normal hit and/or stun hits (not air combo exclusive- press T a moment before impact). Well, as long as you don't charge the P+K.
Testing against the AI (who, if it works like in previous games, techs stuff one frame earlier), ending juggles with 3PP into 2K stomp works more times than 6PK and nets just about the same damage. Seem to work this way because you can input 2K while they're still falling and the stomp will come out.
No I mean characters like Rachel herself, if you do the air throw then 6PK stomp will whiff and put you on _3 when the opponent techs. I think it's -3 for all characters heavier than Helena, -1 on Helena and advantage on any other, btw there is a way to get a guaranteed stomp in a combo after throws with 9P, but I'll keep it a secret and reveal it IF whiff stomp gets nerfed, so far Bass is the only one it doesn't work on.
9P only works after the 426P+K command throw. After the second throw, they're too low to hit with 9P, so you either follow up with 6PK or 3PP. Based on testing, 3PP always guarantees the 2K stomp follow up.