As an atheist in RCIA, I’m glad to see this question asked. It’s a tough one to get an answer to, as it’s so much more nuanced than a distinction between “questioning” and “doubting.” We’re dealing with pretty complex material, here, after all, and a God who, according to the Catechism, is quite mysterious.
You bring up a good point and one that deserves attention.
Too often I’m afraid that, in matters of this kind, the options are presented as two…Accept or Reject. Yet we all know that within and between these two pole positions are many other words, positions and ideas etc that are neither full acceptance or full rejection.
This fundamental idea can be expressed like this.
A person might say, “I don’t believe (this or that) teaching”. They might even say, “On (this or that) I believe the Church is wrong”.
Another person might say, “I don’t understand (this or that) teaching.” They might even say that, “I just don’t see how this can be right”.
In the first case the person is rejecting and defying the Spirit Led Church. In the second case the person is expressing their own limitations and their efforts and desires to understand further.
Each of these come from something more fundamental than simply looking at various teachings. It comes from the basic acceptance or rejection of the Church as Authority and in this there can be no middle ground. You either accept the Church as authoritative or you do not.
If you accept Church authority then then any variation begins from a position of acceptance of what Christ, through the Church, teaches.
If you reject Church authority, even by simply rejecting one teaching that you are required to accept, then you become a church unto yourself…in effect, a protestant…
So - to the OP, having doubts, concerns etc do not make you a “Cafeteria Catholic” so long as you start from the position of accepting because you Trust the Church. From that trust you can then delve deeper into the troublesome teachings and learn the whys and wherefores of why the Church teaches as she does.
Peace
James