I believe I lack context for most of your statements here, since none of them seem make sense to me.

As for my version of instrumentalism (not generally accepted on this forum), I do not postulate any kind of external/objective reality, and hence do not consider terms like "exist" very useful. I care about models accurately predicting future data inputs based on the past data inputs, without worrying where these inputs come from. In such a framework all QM interpretations making identical predictions are equivalent. I suspect this sounds "ghastly" to you.