It's late, so I won't go into details.
Feral Aggression is a worthless talent, if you are feral tank. you use lacerate almost constantly(should) this alone makes shredding attacks a million times better than feral aggression will ever be, even if it is maxed. I am not aware of FB being available in bear form. The bonus to atk power worth practically nothing for your threat gen.
So if you are mainly tank, the only leeway in point would be 1 from Intensity. It is up to you to decide whether it is worth it or no to drop instant 4 rage generation for 1 point in FB.
In my opinion, no.
This is my saved response for cat dps. Since typing this over again each minute a new cat dps post pops up is kinda annoying.
Agility for all gems or mix of hit/agil or sta if socket bonus is worth it or you need gem match ups for meta. Meta should always be 12agi 3% crit dmg meta. Enchants as well Agil, unless its bracer. Where you go with 12str enchant because there isn't a agil equivalent, but if this is your hybrid bracer tank/cat I'd put 4stats on it instead.
Gemming for anything else but agility will lower your comparable dps if you just went with agility.
Gemming for crit/dodge is pointless as you get almost same dodge and crit return from 1 point of agil.
Dps rotation is simple but can vary depending on OOC proc mob hp etc.
Simple one is. Mangle > shred shred till 4 or 5 points if you crit. wait till 80 90 energy, Rip > mangle immediately afterwards. Then shred back to 4 or 5. Let rip completely wear off, repeat. Doing this pretty much guarantees that your dps wont suck. If there is someone mangling for you, simple shred and shred some more and rip at 4 or 5 points and let it completely wear off.
Also there are powershifting, where you quickly reshift and gain 40 energy from furor, if you time it with energy regen tick correctly you can effectively gain more energy which obviously increases your dps.
Of course you must have points in shred talents, avoid Ferocious bite, unless you have almost exactly 35 energy or mob is almost dead and there wont be enough time. But even in this situation, in most cases it is better to just shred.