Perception is one of those "the more's the merrier" since it helps prevent you from getting ambushed. However, via visual/aural enhancement gear, attention coprocessor, and a high intuition, you have a perception roll of 12 with perception 1. That's quite nice, but 15 is better. So I'll leave the choice to you.
As for the arm, that's an acceptable reason. My sig also has the full loaddown on how cyberlimbs work.
As for intimidate, I'll say maybe. Your base roll is 6 and with Steet Cred, you can get up to 8. That's enough to beat most people who aren't faces. You may however have penalties that will greatly increase the chances of failure. It's an appropriate social skill for street sams. On the other hand, your face could quite easily be rolling 9+ dice base*. You have some wiggle room so you can take it or leave it.
As for armor, here's some base outfits. Do you have access to Attitude and/or War? They makes some of the armor stacking easier.
Here's a sample outfit:
Street Wear: 17/14 (you can get 17/15 depending on how you think a SecureTech PPP helmet works or own Attitude)
Armor Jacket 8/6
Helmet 1/2
Full Suit FFBA 6/2
SecureTech PPP Vitals Protector, Forearm & Shin Guards, Leg and Arm Casings 2/4
During play, you might want to think about buying Full Body Armor with Ruthenium. With that and FFBA, you can stack a helmet, and the forearm and shin guards and be at your max.
*-Charisma 5 + Intimidate 1 + Tailored pheromones 3