I don't have a lot of Liu Kang experience, so I'd just have general advice. I assumed his pressure would be more manageable after the patch. What's he using to kick through clones (the string, don't tell me he's using his feet)? Maybe consider trying Unbreakable here to help deal with the pressure/ chip.
As for Kung Jin, the match is easy to explain, difficult to execute. He beats you badly in the neutral, you beat him badly in the corner. In the neutral, know that his NJP is crazy unsafe and you can beat it low profile with slide (even ice ball on a read) if you don't want to risk an advancing normal. Get him to the corner and train him to expect jip as it'll dodge his armored launcher (note that just because he has a response to jip doesn't mean he's going to use it every time. Jin's d2 isn't great and it's risky at that). He may progress the meta to using NJP, trying to beat SZ jip, over armored wake ups). In this case, you have a b2 punish in the corner. Try and predict which option he'll choose and never assume he knows the match up. Wait for him to show you he knows and go from there. Mix in a back dash if he's beating clone with the staff strings and he'll freeze himself.
A lot of people dislike the Ermac MU, along with Scorpion and Mileena. It's character knowledge that comes with time. Don't try to ice skate up hill, some characters just beat the clone. If you're compelled to use GM, tailor your gameplay to punish what it is they're beating clone with. Instead of clone as a failed trap or liability, consider it a bait (punish Ermac teleport with b12, NJP Scorpion flame port, d4 armor shred Mileena ball).
Even before the buff, Cryomancer was a good choice for these guys. Now it should be a great one. They all have very unsafe options that they must commit to, between soul ball after mix ups, teleport wake ups and flip n' roll armor traps. Be patient, wait for these characters to hang themselves, then punish with the highest damage variation we have. While not necessary, try to only burn meter in Cryo when they have no option to break.