For PVE arms, Poleaxe spec is the way to go. So if you have access to an axe (ramaladin, shadows edge etc.) I would recommend swapping specs. Dont worry about expertise, its not that big deal for arms, just prioritize dodge proced overpower over other procs.
IMO dont ditch arp softcap unless you can hard cap Arp.
Other than thats you will have to tell us what is your rotation/Priority for DPS? And what kind of issues are you having to help further.