is there a wood that shoots better for 45#s as apposed to say 55#s or is it all just preferance

Not sure what your asking.

with ceader, pine,spruce, would one work better for a light poundage bow im asking beacuse i have some spruce arrows and they seem to shoot better than the pine out of my i was wondering if it was me or if the wood makes a diffrence

To date I have only shot cedar and lodgepole pine I would like to compare spruce to how the these two shoot, I've heard good things about spruce I really don't think one of the two I've tried shoots any better than the other it's the spine weight and the grain weight of the arrows that determines flight carateristics. a rule of thumb is 9 to 12 grs of arrow weight for every pound of bow weight a 40#bow formula would be  40X 9grs. or 10grs. or 11grs. or 12grs. and wooden arrow spine weight should be 50 to 55#s for a 40# bow That's what I've been taught.