We call them "sacraments", the things that people adhere to as they attempt to live holy lives. I understand you do not use the word to describe things like we do, but which of them don't you agree with? Is it marriage? Repentance? Ordination of clergy? Baptism? Confirmation? (the recognizing of the Holy Spirit). Holy Communion? The anointing of the sick? They are all valid scriptural concepts and surely you cannot in good conscience disagree with any one of them.
Venial and mortal sins are still recognized. Once again, they are just words used to describe the severity of sins. Is grabbing an apple at the grocery store and eating it while shopping without paying for it on par with murdering someone? I don't think so.
I do not delineate sin from sin....they all start in the mind. Then regarding sacraments, I don’t believe in baptism as being critical to ones salvation, nor do I see receiving communion as being a step in my salvation. Honestly, I don’t see sacraments as critical factors to my salvation. However the Catholic Church always taught they were necessary. Let’s take infant baptism for example. In my day a baby Had to be baptized soon after it’s birth because without that sacrament, should it die then it’s soul would go to a place called Limbo (not heaven and not hell— but a place of separation), and of course no parent wants that.
Now if I didn’t go to mass each Sunday, then I couldn’t receive communion and thus not warrant the Grace necessary to go to heaven should I die then and there. Honestly I always disputed that as a kid and now as an adult. That Grace is “Freely Provided” by the Holy Spirit not metted out by the RCC for jumping the hoops of their system.
And I don’t need to go to any priest to confess my sins to.... that’s bowing to another flawed human to give me absolution ( and that’s Gods responsibility, not theirs ).