RCFProd :
Turbo should be enabled by default, strange it isn't. Anyways, yes It's fine even with the stock Intel heatsink.
I think he might be talking about fan speed. Are you talking about turbo boost for the cpu clock speeds RCF Prod? My asus board has built in fan control software and you can set the fan speed for the cpu to silent, normal, or turbo I think thats what the OP is referring to. In any case yes its fine to use turbo fan speed, it might get a bit load under load however. If you are talking about turbo boost for the cpu clocks yes turn that on, like RCF said im not sure why that wouldn't be on by default.