not any harder to learn than any other character I'd say. Just like any character, it takes a lot of practice to get comfortable with her, but you can get there. And she's tons of fun once you get used to her :]
Maybe SC IV PO B+K (Wind Stalker) is now PO 8K, and SCIV PO 8K (Dragon Wheel) is now PO K, with SC IV PO K being gone or another input.
Or you're right and the combined move BT PO 8K is now a safe mid attack throw, blockable though.
I was only able to do BT PO 8K Wind Stalker Attack Throw on the SCV Demo, but i don't know if that would have been blockable or what PO K does.
I've seen a BT PO Dragon Wheel/Wind Stalker-ish move getting blocked though on stream.
So if there's only one PO Backflip/Dragon Wheel/Wind Stalker move it's probably blockable.