I disagree with this. I'm wondering if Christianity as a whole and specifically Catholic are getting confused here.
The primary Christian virtue is love, namely Christ's love for us that sent Him to the cross on our behalf. Without that, we are nothing but sounding brass and clanging symbols and might as well go home (
1 Corinthians 13:2), for our faith is meaningless.
Now, I must give the caveat that universalist or seeker-friendly churches that preach God's love for everyone aren't preaching real love, but rather a shallow form of acceptance. Love is a hard virtue for humans struggling against the sin nature to achieve, and making it happen requires the humility and obedience that you just mentioned. With no humility, nobody would give up their efforts to appease (and thus control) God through good works, and without obedience to Christ's authority, the sin nature cannot be overcome.
One needs to accept the Gospel and then, in the power of the Holy Spirit, understand and obey our Lord's commands. Note that love is first in the fruits of the Spirit, and so it is produced by God's work in us.
Even in the Law love is important, and Christ did not come to abolish the Law but to fulfill it. The consensus of John and Paul would be enough for me to state that love is central to the faith, not to mention the statements by Christ himself, but even the Law places love at the front.
God's love for us is why we are humble; it is why we obey Him, because He has our best interest at heart; and it is why we do our best to love each other, because Christ's sacrifice declares all other Christians worthy of love, because God loves them too. But without Truth, there is no love. It is the Holy Spirit's transforming power that enables us to love and keep Christ's commands.
So humility and obedience are important to work toward love with the Holy Spirit's assistance, but it is important to realize what we are trying to achieve with our obedience and submission to the Spirit, lest we lose heart and view our obedience as drudgery.
If I build a web site according to my self-interpretation of what web design is and what I think it should be, then it will be nothing but an insecure mess of HTML and CSS in a revolting color scheme of purple and red and black that will be hacked to pieces within minutes of it going online. If it manages to survive the hackers, the EU will come after it for violating GDPR and hit me with an enormous fine. In order to do web design properly, one must submit to general human knowledge and expertise about how to program it, comply with applicable laws, and demonstrate a reasonable knowledge of actual design principles, including color theory.
Likewise, in order to interpret the Bible correctly, you need to have proper knowledge and expertise, including a knowledge of the ancient Hebrew and Greek, hermeneutical principles, church history, and a consensus of scholarship informed by multiple people so the sin nature of any one person does not carry the day. Now we can sit and shuffle around which consensus of scholars to go with, the Dallas Theological Seminary, the Roman Catholic Church, the Early Church Fathers, the sons of Zadok, John Macarthur and the Master's Seminary (or even "All of the above!"), the point is that there needs to be a consensus so you don't end up with some wild rogue idea that the Holy Spirit never intended.
There's a reason why we equip and train pastors and missionaries with theology degrees and don't just let them get up in the pulpit with whatever random ideas they got from reading the NIV on a Tuesday. It's not "self-interpretation", it's interpretation in context of the Body of Christ with others to help guide and correct. This is why bible studies exist, as well.
It is possible that we agree more than the quote above reflects. The OP wants to argue for personal revelation over sola scriptura, which is even more unstable than self-interpretation. If you do self-interpretation, you might get something that is at least vaguely biblical; personal revelation is even more unstable and can be controlled by demons.
I would like to know what a Catholic perspective on indulgences is. From your perspective, what is an indulgence?