Technically you can set this up any way you want, as long as you get the staff set nearby in 2D set and get falling j.C or 6C knockdown. You just have to remember not to have too much proration, otherwise they'll be able to tech between j.C 4kote falling j.C and the hits of 6C.
To get the airdash j.CB, make sure you're hitting j.C as early as you can while rising up. Litchi should recover right after she starts falling and that gives you enough time to airdash.
Just to clear up, if you do dash 6kote, don't delay the rekkas (or only delay them a little bit if needed). Otherwise you'll just mess yourself up again.
Also that's my favorite Litchi color when DLC is available :P
There should be a combo with 5B 5C 6D, but I don't think that works from max range.
And 6C[m]'s pushback is awesome, it's going to make the move really safe to throw out.
A small addition for the jBC loop, it will work on everyone if you delay the j.C. However, this only makes a difference in the corner since there still isn't enough time to dash buffer on the characters 5C doesn't OTG.
Anyways, great idea to do this. I know this will help a lot of newcomers who are/were confused with where to start and what is optimal.
2A works pretty well as AA, you just need to learn when it's good to use. If your opponent is trying to get deep jump-ins, 2A should win for free a lot of the time. It gives Ragna a lot of shit, for sure.
Start saving replays so you can watch yourself and see what you're doing wrong, assuming you know what to look for. If you don't, find a way to record yourself and post your videos to get advice from people.
After Hatsu (236B), input RiichiA ASAP, use advanced input to do IppatsuA (press and hold A, this will repeat the input for 5 frames) to do it as early as possible. That's all there is to it, as long as they're at the right positioning.