Floating is better than buried. But just a little buried is not earth shaking.
You can sew all of your seams perfectly some of the time, you can sew some of your seams perfectly all of the time, but you can't sew all of your seams perfectly all of the time!
Be sure to trim your HSTs as Jan suggested, and pin each intersection. Then let come what may and be happy.
There is no way I'm going to flip my piece each time to get the larger piece on the bottom. Just use a stylus, seam ripper, pin or something to ease in the top where the excess is.
What I do is stretch the seam from the front and back as it is going under the needle, then let the feed dogs show me how fast to feed it. I've actually seen someone else do this, too.