I think you have some valid points. I also think I have reached a point in my life where I no longer really question what I believe. I know that God is God and that it doesn't matter what I think or feel. He is taking care of me even when I don't feel very taken care of. He is in control even when I don't understand the big picture. My time on this earth is short and really fairly insignificant. It is to be used to serve others. My happiness isn't my goal anymore. I simply don't feel the need to test anything anymore. If I don't understand, I dig deeper in the Bible, pray, and read other credible sources to see if I can find the answers because I know they are there whether or not I understand them.
That doesn't mean I don't have my days of doubt but ultimately, I realize the doubt is from my limited understanding ... not evidence that God may not exist or may not be who He says He is. I am the variable...not God. I no longer need "evidence". I am already convinced.
I have said many times to people that I counsel with that I have Loved God for so long, I don't know how to do anything else. I'm not sure that is totally true, but I know it is more true than not. But still, and I see you talking about it as well, even with that degree of faith, you still test by reading and studying the bible and praying. These are all ways of testing to some degree or other. At least when we talk about relationship.
Here is an example. At the moment, my husband is at work. He is out of my vision, kind of like God is out of my vision. Now, I can doubt that he is there, or I can trust that he is there, but in the end of the matter, whether my husband is still existing or not, I can "prove" he is by the text I got not long ago and the phone call I will most likely receive in a few moments. My belief that my husband is not a figment of my imagination when he is not standing in front of me can be tested and in that testing, I can be more sure that my belief is true and not delusion. It all comes back to the OP question not to faith in general. With enough "testing" I come to a point in which I no longer doubt. I just know. That doesn't mean that we stop testing or that we can know with 100% anything, what it means is that if what we believe is questioned, we have collected enough evidence over the years to "prove" that what we believe is truth and not delusion.
See, the question was given to us by an atheist. Most (not all atheists) want to make believers out to be irrational twits that don't think, don't reason, don't have a reason other than what they have been taught for their beliefs. Many christians feed this frenzy by saying things like, "you just have to believe" or other comments that resemble blind faith. But from both experience and observation, the true believer who is in a relationship does NOT rely on "blind faith" at all and in fact, scripture paints a very different view itself. When the believer understands this in a manner in which they can express this understanding, then the dialogue changes and truth becomes obvious. I, like you, no longer doubt...but that doesn't mean that the truth vs. delusion question is not being tested every single day, because it is. It is being tested in how I live, in how others live, in how I interact with my Lord and King, with how I study His word, in how I learn to answer questions like the OP, etc. etc. etc. These are all ways to test the truth so that we are protected from delusion by the HS. See, the tests don't protect us from delusion, the HS does, but according to scripture He does through the use of everyday situations where He is revealed to those that will hear and see with spiritual minds and hearts not fleshly ones.
Isaiah 53:1 Who has believed our report and to whom is the arm of the Lord revealed....this revelation is really what the OP is asking at it's heart. What is, or how is the revelation of Jesus Christ revealed to a heart that is dead and cannot reason itself into life. That is why so many get angry when you actually answer the question, because they like being dead in spirit, it is what they know, therefore comfortable to them. The OP question challenges the very notion of what Scripture tells us that there is evidence all around us if we are only willing to open our eyes and see.