Digital BW, The Print

Hi
I have been lurking around this site for awhile and am most impressed 
with the level of knowledge and the over all effort to help each 
other out.

About me
My name is Don Rooney
Live in Northern California (between San Francisco and San Jose)
Shoot with Fuji S1
Am currently using an Epson 880 4 color (8.5" x 11") printer (was 
free with computer and does not use the "chip" on the cartridges)
I'm using the MIS variable mix quadtone inks after going to Paul 
Roark's site and reading what he thinks.
I'm using Red River paper 47# but I see that everyone is using 
something else. 
After making a bunch of regular B&W prints I'm now ready to move on 
to the "real" stuff. But just a note ---- with the Epson default 
driver my prints look pretty good.
So some questions
1. when you actually output are the files RGB or B&W / grayscale to 
start with ?
2. I'm sure I'll get various answers but what is the most used / 
preferred paper
3. Paul -- do you think the 1280 curves you have would be close on 
the 880 ????
4. Is anyone using a reflective densitometer (xrite / gretag) to read 
the black values ????
5. The print exchange sounds great  -- how can I find out more about 
it ???
Thanks in advance for your help and answers.
Don Rooney