DeGrey's read on armor break is 4? B - B punishes "Rook is glowing blue" on reaction (and usually counterhits for 4). If Rook wants to interrupt with no armor or tries to jump you hit C for 1. Otherwise be +11 (or get a counterhit with B - A and get AA followup for 3). Don't use B as a reversal, use it to force a situation if you feel you can.
Air B - B is explicitly a punish for "Rook is glowing blue" so you can get a free 2 damage and knockdown. Otherwise there is basically no reason to continue the string since single air B leaves you plus.
Stringing into C on block is usually not a thing you have to do. Since every grounded normal except bA is plus on block (and bA has hella pushback and leaves you only -4 so not actually punishable), you can choose to keep pressuring with buttons or jump back B/C to gain more plus frames. String into ghost on hit is fine since it allows you to keep pressing after you get your damage.
If anyone wants to play Rook against my DeGrey I'd love a chance to fight. I think the matchup is actually totally fine.