In the account in Gen 2-3 both Adam and Eve sin by disobeying God and eating of the tree of the knowledge of good and evil. However, Eve is not mentioned in Romans 5 (though Paul does mention her elsewhere, e.g. 1 Tim 2:14). This is presumably because Paul is drawing the contrast between Adam and Jesus, disobedience vs. obedience (see Rom 5:15-19). It serves his purpose better to focus on Adam.
This contrast between Adam and Jesus is one uses repeatedly in his letters. He calls Jesus “the last Adam” (1 Cor 15:45). This contrast between the two Adams is beautifully expressed in Philippians 2:5-11. Both Jesus and Adam were made in the “image of God” (v6) but whereas Adam strove to be like God, Jesus did not seek equality with God (v6). Instead he humbled himself and was obedient even to the point of death (v8). So unlike Adam, who was cast out of Paradise, Jesus was exalted and given the name above every name (v9).
Yes (1Ti 2:14 KJV) is quite poignant here. Adams sin was that of deliberate choice while Eve’s was that of deception. Not of course that this excuses Eve’s shortcomings mainly that her “desire shall be to thy husband, and he shall rule over thee.” (Gen 3:16 KJV)
3 “But I would have you know, that the head of every man is Christ; and the head of the woman is the man; and the head of Christ is God” (1Co 11:3 KJV)
This is not meant to start a sexism war rather denote the aspect of responsibility. The ‘Head’ in every case here denotes the Spiritual responsibility one has over the other.
As such it was under Adams lineage (male heir under Jewish Law) that he and therefore Sin was resident in being inherited. Therefore also in this light we see how the first Sin was inherently accounted to Adam and his lineage.
Actually within Romans itself it puts this idea quite succinctly as:
“so death passed upon all men, for that all have sinned” (Rom 5:12 KJV)
The idea that this is the line/derivation of Sin. Of course then in 1Cor 15:54, as you noted, it goes on to deal with Christ and his ‘Spiritual Lineage’. The lineage we are ‘adopted’ into by baptism and belief in the ‘new Adam’.