You can calibrate the speedo with a hand held tach and get semi accurate speed. Like phibert said though, the electrical system is too noisy for a accurate rpm reading no matter where you put the wire. Maybe if the tach wire was shielded...
i use the motion pro tors delete cable with my pwk's and my slides open and close fully. had to grind on the housing of the thumb throttle to let the lever move all the way out though.
same setup here only with vf2's and 35 pwk's and i run 48 pilot, CEL needle on the middle clip and 155 mains. yours should be close to that.
is yours ported? if so, how aggressive? cleanup, full drag etc.
what kind of phone do you have? google navigation is pretty awesome if you have a droid and the map app for the old iphone rom (ios 5 i think) was good. people have had lots of complaints with the new map app on the iphone.
do like ddu said and get a handlebar clamp for it and there ya go.