I think that would be good for arms. that’s what i’d like to see.
Make rend a more powerful bleed and easier to spread aoe, not limited to 2. maybe a bit more core in rotation, and then just change arms mastery completely. It should be like other classes… their main source of dmg increased… Like Shadow priest, uhdk, ret, etc.
Now I actually really do like having a bleed/dot, that’s why i main shadow priest, but it does feel off for Arms to have its whole mastery turned into a dot mechanic.
I don’t know about making Rend stronger. I think I’d rather see it become baseline. I think its duration is being increased in SL but I could be wrong. Would also like to see its rage cost reduced a bit. I feel 30 is a bit excessive.
I would like to see the Mastery changed because I too am tired of seeing Deep Wounds be my top damage for literally everything, as well as wanting more burst instead of drawn out dmg, however it has been pointed out to me it really isn’t as bad as it originally seemed.
Rend is already strong. Only thing is rage reduction for it.
How about make our other abilities hit harder instead 
Although i didnt say it, that was the general idea. The removal of our mastery would in turn make us hit harder, and most importantly MS