I used to a printer tech so I've got a few thoughts.
Don't try and angle your nozzles to try and hit the same spot. The dot shape from each nozzle will be differrent and one color will bleed out from under another. For example a green dot made from cyan and yellow will be cyan on one side green and the middle and green on the other. Space the nozzles apart a interger number of pixles apart and handle the offset in software.
You might want to check out Ghostscript, www.ghostscript.com its a open source postscript interperter (RIP) which as well as all the standard printer drivers can also output simple bit map files with the required pixel on/off type of format.