Digital BW, The Print

I hope these questions haven't been answered before.  I did a search 
and could not come up with answers.

I have just upgraded to the current version of the GUI.  I was using 
a very old version before. I am using a 1280 with UT2.  I am unsure 
about a few of the new features.

What is the best use of the ink limiting adjustment and gamma 
adjustments? 

What is the best paper setting for photo rag?  Should I use the same 
settings as are recommended when using the Roark curves?

Thanks.

Peter