> but I really just want to get a document near the beginning of the year where the IRS tells me what they believe my taxes owed/returned should be.

This is what we have in New Zealand, and it's wonderful; most people simply don't need to do anything other than check their assessment and get on with their lives. Even if you've got e.g. investments you can usually do your filing with no more effort than taking the PAYE (income tax) assessment and bolting on your additional sources of income.

Much like the US banking system, it bemuses me how backward the US is in this regard.