1 Peter 4:1  “…he…hath ceased from sin”
Not that we are perfect or sinless after we accept Christ, but that we don’t live for sin any longer.  We live for Him.

4  “…they think it strange that ye run not with them to the same excess of riot, speaking evil of you.”
I had a supervisor once who invited his workers to a local bar after work for a drink.  I don’t drink so I respectfully declined.  He thought I was strange.  He said he didn’t know what to think about someone who wouldn’t go out and have a beer with him.

5  “Who shall give account to him that is ready to judge the quick and the dead.”
All will stand before the judgment seat of Christ and give account of their actions here.  Those of us who are saved will give account to determine rewards which we can give back to Christ.  It is unclear what bearing their actions will have on those who have rejected Christ.  They will certainly be judged, but how that applies to Hell or the Lake of Fire is undetermined.  If there are indeed levels of Hell, I can’t imagine how someone could tell the difference.

6  “…that they might be judged according to men in the flesh, but live according to God in the spirit.”
Seems to be simple as you read it, but when you break it down it gets complex.  Commentary wasn’t a lot of help as it went into a complex explanation.  Confusion is around the use of “dead,” and to which dead is Peter referring.  Dead as in no longer living or dead as in have rejected Christ and face eternal condemnation?  Commentary suggested standard use as in those who are no longer living on earth.  In that case, Peter would be saying the gospel was preached to them as well as those who are currently living, so that they could also be judged while in the flesh, or alive, and having accepted Christ before dying, they can now live for or to God in the spirit.
I tend to use the term “dead” to refer to those who have rejected Christ, so I sometimes miss the reference when it is simply to those who have died.  Taking that view for verse 5, it seems to make more sense for verse 6 as well.  Jesus is going to judge those living when He returns and those who died before He returns.  The gospel was preached to all so that those who have died are judged as those still living, but having received God’s grace, can live to God in the spirit.
Will be interesting to sit down with Peter in the future and discuss all the aspects of his writing.

7  “But the end of all things is at hand…”
Both Peter and Paul expressed the idea that Christ’s return was imminent.  We need to live with that in mind also.

11  “…do it as of the ability which God giveth: that God in all things may be glorified through Jesus Christ…”
I’ve always wondered how we were supposed to know we were doing things in our strength or God’s since both come through us.  The answer is in intent.  If we do all things for the purpose of giving God the glory, then He will work through us and provide the strength to complete them.  Sounds simplistic, but it is the truth.  I’ve noticed it in singing.  Nervousness comes from focusing on myself and worrying that I will mess up.  Focusing on God and doing the best I can do while allowing Him to be responsible for the results removes the nervousness and lifts any performance beyond myself.  It is also a daily thing, must be worked on continuously.

12-16   Repeat of the suffering for Christ theme.

17  “…the time is come that judgment must begin at the house of God…”
Scripture speaks of the great apostasy that will come at the last days.  I have seen this grow tremendously in my lifetime.  More than ever we as the family of God must examine ourselves and see if there is any wicked way in us.  I believe the sad, immoral state of our country and world can be laid at the feet of the family of God.  We have lost our salt and covered our light and have destroyed ourselves.  May God have mercy.

19  “…let them that suffer according to the will of God commit the keeping of their souls to him in well doing, as unto a faithful Creator.”
We can be faithful servants because we have a faithful God.

I hope you enjoy reading and studying His word.  May it accomplish what He desires.  Please feel free to comment or post questions.  Thanks for reading!