I'd suggest using frame traps
this is a great video:
)
Use 113 to punish strings/moves with poor recovery. Also, don't be afraid to use b2, especially if you've got a plan to keep the pressure on when it gets blocked (mb b3, 113, flip kick, etc). F213 and b13/b112 have good reach and are worth putting out there every so often.
I don't personally use d12 too much because it opens me up to overheads and since it hits mid, the payoff isn't that geat (d12-4-mb ground spark- b3 - j3- 1- flying grayson is my go to combo from this string and does 35%). I use 113 most of the time in it's place; it's faster and prevents overhead mixups.
I don't believe you can throw while your opponent's in block stun. However, dashing in and throwing after a string, especially ones with quick recovery, is an excellent strategy.