Digital BW, The Print

I am ready to switch to MIS U7 for my 2200.  

(1)  Can I use both Eboni Bk and Pk (and in what position, if so) at 
the same time, so I can print on both matte and semi-gloss or 
equivalent without switching ink?

(2)  To switch back to Epson OEM for color printing, do I need to do 
anything special to clear out the MIS inks or vice versa?  I do about 
50/50 printing (color mainly for family pics) but tend to do them in  
batches.

(3)  Is the 1280 a good printer to dedicate to one or the other with 
MIS inks?  Which?

Nancy