I overall have a great deal of agreement with everything you wrote. Just a few quibbles worth elaborating on.
First, I take it as a given that my own perspective is not reliable on it's own. I interpret the world through mental filters that bias my interpretations, fill in gaps based on assumptions or expectations, and otherwise operate as a flawed instrument for converting inputs into a perceived reality.
Second, while herd mentalities get a bad rap among teens, hipsters, and iconoclasts, consensus serves as a critical tool for correcting the problems that come from the first issue above. The scientific method is a formal means of doing this but we are biologically primed to do this informally because it had survival benefits for those of our ancestors who had this trait. Someone looking over an ancestor's shoulder who exhibited fear or shock, causing a reaction in return that resulted in dodging an incoming rock or predator, had value that translates into inheritable impulses to have concern for the perspective of others. If I see one guy on the street ranting at the sky while others walk around him going about their business, I may or may not take a glance in the direction of what he is looking at. But I'm going to be skeptical there's anything there even if I do. If I see most people on the street starting to look up in the sky and expressing an emotion of some kind, I'm definitely going to look and anticipate subconsciously I'm priming for fight or flight. Likewise, I like to check my own understanding coming out of meetings with others who were present. I look for information that is arguing against my views precisely because a strong argument that contradicts my own assumptions and worldview is quite possibly going to lead me to a better understanding and thereby greater trust in my own thinking. In short, reality that is confirmed by others is more trustworthy to me than reality that only I perceive.
I have to emphasize how much agreement I have with you here. I might even go farther than you, our belief forming cognitive faculties are narrowly reliable. Their reliability comes from necessary wiring for our survival. These "brain bugs" as Dean Buonomano calls them in his book of the same name are extensive and can wreak havoc on a believing mind in myriad ways. I have said this before but it often times doesn't seem to stick. When we really look at our belief forming cognitive faculties a belief in for example a creator that loves us simply can't reliably come from those faculties at a basic level. But faith isn't believing things that just aren't true or without any evidence. Faith begins as a fundamental trust towards reality. We develop a fundamental trust towards reality itself in order to survive. We also develop fundamental trust toward that innate sense of there being something more. Or we don't. But those developments of trust from inside us shouldn't be confused with our everyday decision making, thinking etc..
Third, moral arguments that imply an ought of some kind seem to require another who will be affected by my thinking and the resulting actions that arise out of it. Otherwise, what purpose does an ethical system service if it isn't for easing the frictions between individuals towards some societal aim?
Individual aims as well?
Fourth, I am much more convinced of the existence of other people than I am of the existence of a metaconsciousness.
To me it is incorrigible. When one really understands idealism and arguments for all the different isms, a sincere intellect in my estimation can only conclude, I don't know. This is why we should not commit one way or the other. but trust remains for those that are constructing views based on all of their concrete human experience based on trust.
As an aside, one of my biggest issues with Mormonism since leaving it is the emphasis on moral laws as the basis for ethics that creates morally underdeveloped people if one instead assumes a morality based on trying to not hurt other people. Religious systems that treat morality as primarily between God and an individual create moral disabilities, in my opinion.
I agree wholeheartedly. I once was one of those disabled, probably still am but accepting my disability.
Last of all, I assume the premise behind idealism is essentially true - reality as we experience is a construct of our own minds -
Yes and no. That portion of idealism finds a wide spectrum. Kant probably wouldn't want to be mixed with a biocentrist. Hegel and Schopenhauer were further than Kant. I find idealism in a pure form as consciousness IS fundamental reality. The conscious experience we have is steps away from that. We find our conscious experience IN consciousness. Our world is consciousness.
mikwut