Bad/Weak water pump?????

Well yes, it could be the thermostat and yes pump impeller freewheeling (rarely). How was the coolant when you drain the radiator and changed the hose, any settlement, maybe rust, dirt? Can you look closely into the top of the radiator and see if you may have crust around your radiator flow tubes? Has anyone mention fan clutch? Drive your car down the highway get it where you feel its getting hot, pull off the road, shut the car down, jump out, open your hood, try to spin the fan, if it freewheels you have a bad fan clutch, a simple test. Normally the fan clutch being hot would have a great resistance to spin. Hope this helps. I have to ask looking at one of your pictures, I notice the by-pass in a large U shape, looking at my car it is mainly L shaped...something maybe kinked?