The OP makes loads of decent points, what really frustrates most is it should never have happened, we've had a consistent problem that when we are strong and at the top of our game we fail to strengthen, it happened the first two times we won the premier league, and it happened in the last two windows.
Our transfer dealings last summer, needed two things - centre half's. Kompany left and Otimendi (who was 4th choice for the previous two seasons) wanted to leave. Instead we signed Angelino and Cancelo who add nothing to our squad, and Rodri who is decent and will improve, but that position should have been filled the previous summer when we missed out on Jorginho and ended up with Mahrez.
With two centre half's we'd have coped with the loss of Laporte for half the season, and not weakened our midfield by moving Fernandinho to centre half.
The powers that be at the club have messed up this summer/season, which is a huge shame as now we have to watch Liverpool win the league when we should have been looking at taking third title in a row.