What should Hisui do on wake-up?
Block.
Yes I'm serious. Things like jumping straight up, back dashing and the like are character / situation dependant. Outside of that Hisui has no specials worth using as a reversal, and that includes ex-ladle.
And what are the pros and cons of 5B?
pros - Really awesome priority, has clash frames. Good to use in block strings, stuff an opponent from wake up jumps.
cons - lack of range, doesn't look sexy.
Also, is the stuff-fu command 2142A or Ren-style 214A2?
Stuff-fu commands:
2142A - Just pot, comes out very quickly, good to use to control the air. Peak of the arc is higher then pot books, so it covers less space horizontally.
2146A - Just book. Also comes out very quickly, hits twice and has clash frames (if I'm not mistaken). Tiny bit of frame advantage on block.
2141B - Pot books. Both pot and book come out together, excellent way to control space and as a means of getting in. Comes out slower then using them individually, but still really good. Pot here comes out slower but has a lower peak in its arc, so it covers more space horiztonally then just pot.
21416B - Tray books. A flying metal tray and book come out together. Tray comes out VERY fast, good to use when you want to force your opponent to into a situation, or to keep nailing them from across screen if they're attempting to set things up (Aoko for example). Book also comes out.
Those are the ones you should be using primarily, the others aren't all that hot.
;p