Did something similar once -- I am assuming that the metal is US -- and I recall that once I had my US DM mileage in the system, I was able to act as though it were a US flight : there should be a US confirmation number as well as the UA confirmation number ; and the former should allow you to choose seats as US (although since you are not
yet Silver, doesn't really matter). Anyhow, I don't think that you will be discriminated against (other than via the random outrages that arise if you fly enough) ; and posting of miles should be as per normal.
Anyhow, my experience ... or recollection thereof
