Personally, I do think God is all powerful and did give humans free will. I believe God created humans for relationship with Himself. I think He wants us to choose to love Him.
I think God is pwerful enough to keep His Word for us. Sure, there are English translations and words used in my Bible that may not be the same as the original. So, we have learned to look to the original for the correct translation of a word. I do not agree that it would take a lot of interfering to keep it pure--not with the original.
As far as your examples of literal vs. not as protestents--well, that is interpretation. Whether you believe the bread and wine to turn to blood or body is not something that your salvation depends on. I believe Christ was saying "this is (represents my body), take and eat"...etc. My Catholic friends would say it turns to the actual body once taken. Although these are different views, they do not matter in the plan of what they are or why we do them. If they are just bread and wine, they'll be just bread and wine for the Catholic also. If they are His blood and body, they'll also be that way for me when I partake of them too.
Maybe I am supposed to have a head covering in church--that isn't something I do and I might be wrong for not doing it. I'd have to look into it more to give you a thought.
I think the Bible is pretty clear on works and salvation. Salvation brings works but works is not required for salvation itself. If I am saved and not doing works then yes, I definitely have trouble there and it would need to be looked at. But there is no work that will earn me Heaven. Jesus's Work did that for all of us who choose Him.
I've been dunked as I believe Jesus was also by John the Baptist. Is sprinkling wrong? I have no idea but personally do not think it is. I do not believe baptism is a requirement for heaven although I do believe if you have time and can be baptized, you should do it as an outward sign of what has taken place within your heart and life.
I respect your thoughts and views and I'm sharing mine with you. I believe the jist of the bible is to show the lineage of Christ, whose life was planned by God aa the way of salvation for sins for His people. The stories of the lives of Abraham, Noah, David etc. show us many things about life and about the nature of God. These people were part of the linage of Christ (IMB) and their stories are of value to me and, I think, to all of us.
I believe that the plan of salvation through Jesus Christ is so simple that interpretations cannot change it. We can add all kinds of church and denominational rules around it but it is still what it is. Man-made rules are just that, man made rules. I do think man has taken liberties with the bible and tried to twist things into what they want it to say or a way to control people or a reason to fight when God was not leading. Those things are wrong and I feel people will be held accountable for it. I just think people tend to try to complicate a very simple plan that God planned for man once sin entered the world.
I do not have all the answers; I am filled with lots of questions myself. But honestly, none of the questions make me doubt salvation through Christ. They are more or less just details.