Either you have a blockage or your water pump is not working at all.

Since you have had the system flushed. Try turning on the heater and see if that makes a difference. If it does not there could be that there is no circulation which could indicate a water pump failure.

Water leaking out of the water pump outlet does not indicate a total failure of the pump - rather a bearing failure.

If your auxillary fan is not cutting in that this does not indicate a sensor failure for this.

Are you sure that your water temperature gauge is indicating correctly?

As already mentioned above. The fans are irrelevant when cruising at 50 Mph or even Kph.