have dealer do it?

i am and prolly always will be a tech for honda, have you checked/lubed the shift linkage at the pivot point on the trans?? it kinda sounds like a binding linkage to me or a bad bushing in the linkage. I have some of the same complaints as you with my trans in my car, some days it feels great, others it feels like garbage. it finally came down that i had a bad bushing in one of the linkage couplers, changed em and wow what a differance, have you put in a short throw or anything??

redline is great for bearings, but it tears up sychros because it is just so slick, maybe it doesn't have such an adverse affect in a 2wd car where it's easier for the driveline speed to increase/decrease rapidly but for the most part i would never use it. i would just stick the manufacturer reccomended fluids for a street driven car.

as for the synchromesh: it's not reccomended for honda transmissions, in older trans it prolly works fine, but the newer trans's uses triple cone synchro's with clutch packs versus bronze blocker rings on certain gears.