This valvetrain has adjustable clearances. It´s possible it is out of adjustment. You may also want to pull out and clean the auto adjusting camchain tensioner. Sometimes they jam and they don´t take up the slack. This can add to noise. It is also normal to have a little rattle on the chain that runs from the crankshaft to the transmission. The teeth on this chain are designed to take up slack in the chain once the rpm´s rise a bit. Your idle should be from 950 to 1150 rpm when warm. The case-hardening on the cam lobes is pretty tough. Unless you´re using varsol for engine oil it´ probably not as bad as you think. Once you have your bike fixed up, try using a 20w50 oil if you arent already. If you arent using this oil you will find the bike to be quieter and shift smoother too.