Kazuya has a very anoyng 50/50 gameplan, that you can abuse a lot. Learn to wavedash, do EWGF from wavedash, hellsweep, and some mids and thats it, with this gameplan you can reach the red rangs easisly xd.
Use more the EWGF, its the best move in the game as it leaves you in +5 on block
Jin is a real pain the ass with his pary, that evades even unblockable hits, and those string are also op, im on ryujin rank and still struggle a lot against jins from lower rangs.
Wish you good luck on your learning! If you want to train we can play on steam.