Q1: As for your first question, Floor 2 only answer you one point.
There are still others problem.
1. Cleaning head is one way.
2. Do alignment is two way.
3. Rip Software control Epson 9600 Paper feeding is third way.

Q2. it depends on which Rip software you have used.
If it is old version of Best Color, try to upgrade to EFI Colorproof XF 2.6
There 3CC Calibration function, it may help you.

检查一下色彩管理软件里的参数是否一致，特别是ICC

这个办法不一定行,
问题1：打印的分辨率是多少，1440dpi的效果要好一些；
问题2：打印机的线性有差异，同样的参数打印效果不同是正常的，解决办法是每台机器单独做线性曲线。