The examples you gave aren't exactly convincing.
After reading what you say, right back at you.
Here's one.
"she can parry on Bass' backturning throw combos (parry while back turned)"
Leifang can parry Bass when BT, but Bass can also grab or OH her. And why would you use that grab out of the huge list of grabs in the first place, if you know she can do that? It's a 50/50 guess anyway. Bass gets more grab damage than Leifang gets for parry damage. No advantage for Leifang here.
BT T gives +21, 2T +10. If you get it you are looking at an easy 30%+ strike combo against anyone who doesn't have the tools to stop it. Why not go for it? Grabs can't do quite that without either a charge or going for his TFBB.
Explain to me why she doesn't need to break defenses. What exactly can she do to just chill? What are these godly moves that Leifang has that leaves bass at such a huge disadvantage? If Bass just stands there and blocks, waiting for an unshu or a chance to grab, Leifang can't do much. Her attacks are not gonna get her anywhere, unless the Bass player makes a mistake. She needs to use either grabs or OHs to get anything respectable by chipping away damage. With his neutral 4 frame grab, he can punish unshu every single time if he pays attention. She relies on counter hits to get anything going, and if the Bass player barely attacks, she's simply standing against a big rock. If you're trying to spam attacks with Bass you're doing it wrong. Just because the Bass player can't attack like he's playing with Christie, doesn't mean that it's a very bad matchup for him.
Something about Unshu on reaction doesn't seem to come to mind with you. You don't throw it out whilly-nilly, same as holds. Bass is slow enough on strikes that an Unshu on reaction is all it takes.
Bass needs to be careful while attacking, but Leifang needs to be very careful when using her best tools. It's not an advantage for him, but the advantage Leifang has is not as big as people say it is. I invite any good Leifang player to play any good Bass player, to see of you'd just chill.
Unfortunately a Bass always needs to be careful no matter what he does or who he fights. Throws, OHs, Pickups, GBs, it doesn't matter. Lei Fang isn't exactly in the same book.
Bolded.
So we are both going to debate why Lei Fang has the advantage?