Riichi = 63214A/B/C while staffless, the most commonly used version is A
Ippatsu = A/B/C while standing on the staff (after Riichi), Tanki Hatsu (IppatsuB) and Tanki Chun (IppatsuC) are just other names for it. If you see Ippatsu or Tanki Hatsu/Chun listed in a combo, always assume RiichiA was used before it.
She is playable on pad, however you may have to use the claw-style holding where you use your index and middle finger on the pad, as if you were playing Tekken.