Yes you can, and there is no need for a PCT because it isn't suppressive. It is suggested to cycle off of it every 16 weeks or so, for weeks.
I would use GW501516 as the base of any stack or cycle. It is also fine on its own if you goal is straight endurance.
You won't feel wired like you are on speed or any type of stimulant. You will just notice that you don't seem to get tired as easily or for as long. So far it is my favourite.