Gangplank has counter picks so dont take him before looking at the others team champs. His hardcounter is pantheon dont pick Gp if u see apantheon in the other team. All the champs who have a shield are good too against Gp like mordekaiser, shen, malphite, udyr...

This build is an offtank build thats why u havent so much damage and u cant give critics in early game. There is not lot of critical chance because if u start by infinity edge for example you will be raelly too squishy against the other solotop and for the team fights. I dont like only critics build GP isnt a carry AD its a melee so you cant go in the melee without tanky items, if u just use your parrley you will deal so less damage in team fights than a real AD carry cause of the CD.

Flash and exhaust are the best summoner spells on gangplank cause u are a bruiser and ur role is to focus the ad carry so thats why i take exhaust. But teleport can be a good spell too to come in your lane faster and dont loose xp and gold.

You can max Remove scurvy if u are beat on your lane its will give you more substain, but if you have the advantage raise morale is better its give you a lot of AD and dont forget to activate it when u are fighting

Its offtank runes with DPS armor and magic resistance for late game teamfights

You can jungle with this build if u have all the runes the only thing u have to change is to take raise morale lvl1 paarley lvl2 and remove scurvy lvl3 after that make the same skill order