I hate to bring this at this time, but... a huge river draining such a wide basin would have a very important feature that is missing..
Furthermore, if it drains temperate/cold land, where you have melt waters every spring.

There has to be a wide stretch of land, on both margins that is seasonally flooded. I mean, nearly as wide as the river itself and with some meandering.

This would be suitable for farming but not for building houses. Those two hills and the islands could mean that there are rocky outcrops in the area and those could be used as suitable ground for building, but you cannot have it overall. (in my humble opinion that is)