Oil height mainly controls bottoming resistance. It has little impact on how the fork reacts to sharp hits like rocks and roots. If you reduce the oil height further, your forks will still be harsh in the rocks, but will bottom too easily on jumps.
The lighter oil weight will mainly reduce your rebound damping and have minimal effect on compression damping.
MX valving usually has too much high speed compression damping for rocks/roots.
Factory Conection does a great job with CR suspension for the woods. I briefly rode an '01 in the woods, and the stock forks sucked compared to my Factory Connection suspension.