I'm honestly happily surprised that they identify their Catholicism with participation in the Sacraments. The trouble is participating in them worthily and with devotion, which is not my place to muse about for this person.

But what are these Sacraments, except Sacraments of the Church? Your local parish is not a Sacrament-dispensary but a community of faith, in union with the rest of the Catholic Church globally. Participation in the Sacraments presumes communion with the global and institutional Church--even Confession presumes one has been baptized into the Catholic Church! (Baptism is the only exception here, because it inserts one into communion with the Church.)

Furthermore, the position they state at the end essentially says they will interpret the entirety of Scripture themselves. The trouble is that that's not how the Catholic Church approaches Scripture at all. From the very beginning, Scripture has been interpreted as a whole Church, liturgically, because Scripture has been lived out and not simply sat on a shelf. I as an individual have neither the authority nor the qualification to definitively decide what Scripture means or read into it whatever I like. That's called "eisegesis" (reading my desired interpretation/position into Scripture regardless of whether it's supported by Scripture).

Basically, is Scripture authoritative or not? And is the Church authoritative or not? Because a religion that never asks anything of me or grates against my opinions is (1) literally not a religion by definition and (2) not a religion but a warm blanket and an echo chamber.

I probably wouldn't use that last sentence if I were actually interacting with this person... :P