You do have a point on 1 John 1:9, I generally use this verse in reference to sins we commit after we are saved. My point is there is no reference to only a select group having their sins forgiven. The verses are all general not a specific group like the Jews, or the Elect or other specific groups.
I have always interpreted 1 John 1:9 to be for the unsaved (forgiven) and the saved (cleanse).
I don't need my sin forgiven, they were forgiven at salvation, but I need to confess and be cleaned to restore fellowship. A sinner must confess that he is a sinner in the need of a savior to be saved.
I may be reading too much into the verse, but I don't think the concept would be un-biblical. Why would John and Paul not be clear that not everyone has the option to be saved.
I have always believed predestinated to mean God knew how we would choose through foreknowledge, but created us to make our own choice. Everyone has the opportunity to be saved, they just may choose to reject the opportunity. I could predict what food each of my children would choose at the buffet line but they had the freewill to choose whatever they wanted. I also had the opportunity to influence their choice but did not always take it just as we don't always take the opportunity to tell others the gospel story.