Hi MadHatter.
Salvation is a free gift from God for all those who believe in Jesus Christ.
Works according to the Bible would be any act that God considers righteous. Feeding the poor, comforting the widow and the orphan, defending the defenseless just to name a few. Notice I said, "God considers righteous". Human righteousness is not to be confused with Godly righteousness because it can never reach the zenith of God's righteousness. Many things that humans consider righteous, God does not. God sets the standard for righteousness.
Isa 64:6 But we are all as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away. (KJV)
As for lazy or unaccomplished Christians, it is not our right to judge them. If they claim to be Christian then they will live their lives accordingly to the standards that Christ set. God will eventually judge them based on His righteousness and not theirs.
Anything that we may try to do without the love of God within our hearts and minds, is as filthy rags before our Father. In time, our flesh bodies will get old and weak with all the frailties of old age, and in time each of us will die. However, for those iniquities that we commit in the flesh, we will be held accountable even after we have left these flesh bodies. That is why we must be very careful that Christ's redemption comes through each of us. It is only through Christ's redeeming blood and our repentance and faith in that finished work that our perfection can be brought about. Once we have repented to the Father in Jesus' name then we are brought in kinship with our Lord Jesus Christ. This brings about our salvation, for we have accepted Jesus Christ's righteousness to be our own, because it was His blood that paid the price for our sins.
MadHatter wrote:The minimum...is there a minimum? Does it matter?
Matt 10:42 And whosoever shall give to drink unto one of these little ones a cup of cold water only in the name of a disciple, verily I say unto you, he shall in no wise lose his reward. (KJV)
Hope that helps you.