You don't need to mark anything.The timing of the valves and ignition on these bikes for all intents and purposes cannot go out.Once the cam chain has been correctly fitted to the marks inside the engine to the Woodruff key on the crank shaft end they are set.
Yes you can remove the front cover without removing the clutch cover to check the oil pump chain.Whilst there clean the sump and remove the oil pump anyway and clean it's gauze filter.This is often over looked and gets clogged reducing the efficiency of the oil pump.
Note:When you remove the front cover several things usually drop to the ground like the oil dowels and their o-rings and sometimes the oil pressure regulator.
It's a small alloy insert tube which must not be left out on re-fit and also must be inserted the correct way round with it's associated o-ring.
Also when removing the oil pump a similar dowel and o-ring may drop out.Do NOT over torque the Bolts on the oil pump.They are supposed to be around 9 ftlbs but as this is too low to be accurate on most torque wrenches I use the knuckle of my Socket wrench,not the arm and a dab of torque lock and do them sensibly tight.I use a large screwdriver to prise to make the oil pump chain to it's correct tension.
Also if you have the time and will I actually strip and clean my oil pumps flushing them with carb/brake cleaner and then high pressure air blowing them and check their service limits as per the specs in the manual/s.They are not very complicated and are quite robust.
I also fully flush the front cover and it's pipes.
HTH
