Vibration, no but excessive bounce or wheel hop, yes.
Yes, just like any other truck.
no,not truck shocks, but you can use spring helpers or you can order a lift kit for the front and for the rear you can get air shocks from your local parts supplier.
rear front or rear?
Front shocks. You may feel what I could describe as an "UP" bounce feel. If you replace the front shocks this will minimize that feel. However, the Frontier front suspension is quite "bouncy" good truck.
Stand on the front and rear bumbers, and bounce the truck up and down then jump off. the truck should bounce once are twice. If it bounces more then that, replace shocks.
That truck has shocks on the front and rear. Standard shock absorbers do not carry weight.
Right behind the a arm in the front on the back on the rear end
Brakes, wheel bearing.
Upper ball joints need replaced
most likely it is a cylinder missfire it might be a broken flywheel (cracked)
If it is while you are braking, the rotors or druma are warped.
Yes