Digital BW, The Print

Some questions on Epson RIP for 2200:

1. Does the RIP produce better results than just using the Epson 
driver for the 2200P from Photoshop?   If yes, why?   

2. My limited understanding of any RIP is that if off loads printing 
to a separate computer, adds functionality in setting up print jobs, 
supports postscript, has functions such as ICC profile to profile 
conversion, etc.             

3.  Another post on this group stated the user achieved a neutral 
wedge for semigloss but not EEM.   Are the gray scale wedge results 
neutral for EEM, lustre, semigloss ?