214c in/near corner: (j.C) (2a) 5B 2B 5C 214C 2C (2 hits) into either a) 5C 214A Air Throw or b) Wakeup crossup from 2C
As for 22C it depends where you are.
If you're in the corner you can probably get away with anything. It's untechable. Just be creative. I haven't tested these much but check to see if you can get a 5[C] in.
If you're at least the a screen away from the corner you will be looking at something involving sj.[C] into 5[C] into something. Once again, be creative while keeping proration in mind.
I don't know about cross-ups during blockstrings. I don't recall ever going for them myself. If your opponents are poking out, in general, you want to stagger your strings better and train them to block. However, if they know what Sacchin is capable of, and the fact that you give up so much by jumping over your opponent, it shouldn't be very hard for your opponent to escape once you take to the air.
Don't forget about fake j.[C] throw if you don't think you'll have enough time to do a bite.