Layton, yes, I was referring to the larger shims closest to the piston. As far as number to remove....trial and error...make little changes at a time and document results.
I doubt you will have much success with the lighter oil, but it is an easy change :D .
As far as what you are trying to accomplish, you must try to think of your suspension in terms of speed that suspension is moving up and down, not trail speed. Try to think about the particular area you are having problems...now, is the suspension forced to move quickly? or is it a very slow movement? Try to think of the bump in terms of distance the suspension has to deflect vs. the time it has to accomplish this (relative to forward speed and steepness of ramp, or bump face).
In my experience, most "harshness" people feel, with MXers in particular, on trails is usually not a LSC issue, usually actually the faster ranges that are the problems.
Do a search for "shim shuffle" (part 1, 2 &3). THis thread when on for some time (and actually 3 threads) and talks about some of the issues you are asking about. It might help clarify some.
Your problem may also be spring related too...