First, you guys were right about Lizardman. He is fucking weird when it comes to that throw. I had a guy JF tech out of the command throw BEFORE I let go of B, and I got the JF. Whatever.
In general, though, command throw -> ground throw isn't that reliable unless you're at the edge or near a wall. The timing is very exact. Better off going for 6B+K if you need damage.
214AAA is so wonky in SC4. It'll whiff if they step, since it doesn't always track, but if you're whiffing the last hit don't forget that you move while you spin. Hold 6. The followups are much less reliable. On block your throw will beat everything but they can still duck, on hit a few characters yield free crouch throws (iirc Amy, sets, mybe sk?). The rest you should get a 50/50 crouch throw/ground throw mixup, depending on how they fall (if they're off axis you won't get the ground throw).
But, yeah, the BD changes for Rock were really good, but you should be able to adapt. 2B+G, B+K is good in BD, but it won't work against most characters in SC4, everyone else can tech. But the 9B, 6B+K combo doesn't work in BD. Also watch for less RO range on his ground throws.
And if you spam more crouch throws vs Lizardman they'll probably stop going into crawl altogether. It's pretty gross; I think you get a crouch throw on crawl A even if it hits.
After 3A+G, B+K ground stun if you dash you can catch tech with a crouch throw. 3A+G, B+K -> 2B+G, A+B = Rock Doom Combo. See if you can land that, cus it's manly as fuck.