Digital BW, The Print

Hello

Today I downloaded QTR for my Epson 1290 printer with MIS UT2 inks. There are several 
paper profiles delivered in the package, but none for Epson Premium Semigloss which I 
prefer so far ( I´m a beginner in digital printing). Which profile should I use when I print on  
Semigloss? 
Another question: Is it a must to work the pictures in grayscale. Until now I scanned my 
Ilford XP2 negatives to RGB workspace and edited in this space but he QTR documentation 
recommends printing the pictures in Grayscale. What´s your workflow?

Thanks
Julius