Although God does choose individuals for certain purposes which may or may not have anything to do with their salvation.
God does nothing nebulously.
When a passage of Scripture doesn't make good sense to a person, it is not saying that Reason trumps Scripture, for that person to look about for another way to see that passage of Scripture.
The real problem with,
"This is speaking of us, all the faithful collectively, not choosing individually.", is that it just doesn't make sense. It's pretty obvious that cause-and-effect is pervasive, and that chance cannot cause anything, and that God is first cause, which means that EVERYTHING that is not him is what it is by his plan and purpose. I don't mean that God does nothing collectively, but when he does, it is individuals to whom he does it.
Even in Heaven the Bride of Christ, a collective, is made of individuals.
I'm not sure I fully understand what you mean. But sure some preconceived basic ideas are natural, like Jesus dying and being resurrected and that sin entered the world through the fall of Adam. Those are basic truths. When I read the Bible I try to read from the "basic truths", not from ideas like predestination, total depravity etc. So to me reading the Bible is trying to read it from a mind that is as much as possible blank from doctrines, to really read what is says and not says. Sure context is important, won't argue there. But it's important to not study the Bible with already formed doctrines in the head, as far as that is possible.
I don't think you will be convinced from reading the Bible alone, but from studying the Early Church Fathers. So it depends on how much you invest into that, and what importance you give the teachings of the Early Church Fathers.
Should one also bring to the table, a blank mind, as far as reason is concerned? There is certainly value in reading with a mind like a child, but there is also value in maturity, which includes not only Godliness, but wisdom, knowledge and understanding.
Whether by 'doctrine' you intend such things as the tenets of Reformed Theology (or any other theology) or not, we ALL —even the unbelievers— have theology; we all have our doctrine. We also have our worldview, which is impossible to shed, though wise to bear in mind that we do have one (not at all saying that our worldview cannot change —it is constantly being revised, as we learn and mature).
(Ha! Personally, I find the attempt to read without preconceptions distracting. How does one do that? I remember taking a speedreading course, but found my mind incapable of following the method, simultaneous with paying attention to what my eyes were scanning!)