1) Timing cover's O-ring may be replaced without draining oil. Like the valve covers the oil seal is accomplished via squeezing the O-rings rather than strong compression of cover itself to head via overtightening of the cover bolts. So replace o-rings when they look deformed ( no longer round in cross section) and use minimal torque when re-tightening bolts.
2) Timing really can't be "adjusted", it can just get screwed up so that the bike won't run. One, and only one, correct timing sprocket tooth-to-timing chain-to crankshaft gear position exists. This is very, very easy to check. If you have not purchased, or downloaded the free TW Service Manual you should do so; then read and perform some of this simple diagnostic and maintenance tasks yourself. No need to wait for, or pay for a mechanic to do basic inspection, adjustments and maintenance.
3) I will be so jealous of the Waimea Ride. Where will you be starting out from? Waimea.jpg