Explanations/Questions:

v.1-4,  The "I exhort" of v. 1 is really a part of Peter's discourse pointing to "shepherd" (v.2) as the primary verb of this whole unit (v.1-3). Normally these verbs of direct or indirect discourse do not get separated, but Peter attaches so much weight to "I exhort" that I felt compelled to distinguish v.1, leaving v.2-4 as the 'Content of his Exhortation.'

v.1 Question: "...a witness of the sufferings of Christ..." Is this a reference not only to personally witnessing Christ's sufferings, but also his own experience suffering?

v.2-3, It is the series of "not-but" conjunctions that pushed me to give each a separate arc even though each phrase contains only an adverb or adverbial phrase. The subject (you) and predicate (shepherd) can be borrowed from v.2a.

v.8-9, There are no explicit conjunctions linking the three imperatives, be sober-minded, be watchful, resist (the adversary). That the adversary prowls like a lion easily supports all three, giving amble cause to be alert to his schemes and resist him and so I had initially arced these verses as Bi-Lateral. However, I chose Ac-Pur to emphasize the aim of the alertness - so that we may resist. In other words be prepared to resist by being alert.

Major Arcs: In v.1-7 I see three units addressed to groups within the church: to the elders (v.1-4), to those who are younger (v.5a), to all (v.5b-7). v.8-11 complete the whole letter with instruction that progresses toward a crowning promise (v.10) and finally a strong doxology.

Summary: Peter wraps up his letter with instruction for the church community, first exhorting the elders to shepherd the sheep God has entrusted to them with a care that happily looks to the best interest of the sheep, not the shepherd; for this God has a great reward for his under-shepherds. This means too, that the sheep need to follow the elders' lead. Humility is to be the distinguishing mark of the church as a whole, for God stands against human pride. God's aim is not to have a down-trodden people, but to exalt those who have dropped their self-serving pride. Humility then, particularly in the context of suffering, is to throw all one's fears, indeed one's whole life under the diligent care of the Lord.  Peter pushes further, recognizing that the Christian life is not a passive, "let go and let God." There is an enemy actively seeking to destroy faith. And so he calls belivers to be on high alert - sober and watchful- so that they may, in the stability of faith resist the adversary alongside fellow believers fighting the same battle all over the world.  Peter crowns these instructions - and the whole letter with a view, once again, to the ultimate end of all things including suffering. His words are direct and personal: God, the sum and source of all grace, the one who has summoned you to join in his Son's own eternal glory - this God will himself restore you, confirm you, strengthen you, establish you. To this God be full dominion forever and ever. Amen!

Insights:

Consider this passage in light of John 21:15-19. Peter has throughout this letter been thoroughly pastoral: encouraging gently, exhorting firmly, offering instruction firmly grounded in Scripture, always aiming at the growth and maturity of his readers in faith and holiness.  And none of this is dispassionate or disconnected as though from an ivory-tower leader, but from a fellow elder feeding his own flock.