A humber wide LEP would not create a south Hull type setup, it is more of an economic reason why it should be persued, though it is not unreasonable to expect that some suburbs would spread to the south bank should the tolls be scrapped. People are already noticing the cheap cost of land on the south bank (due to bridge tolls) and are building houses and travelling to Hull for work. If that was to increase, then there would be better public transport due to demand and a greater link up between the towns on the south bank and Hull.
I would have asked for more examples than just Rotterdam about why city regions dont work if they are seperated by a river, and from what you say it sounds like a whimsicle remark based upon Rotterdams experience, in fact most successful cities are built on rivers with well worked out port infrastructure. New York anyone? London? Oresund which actually transcends both Denmark and Sweden and is connected by a much longer bridge and tunnel than the Humber Bridge, resulting in a highly successful and growing economic region.
As for the rest of the post, very interesting. At one time they were saying that Hull has no tall buildings due to the ground being too soft, and that they would just sink. Hmm. Got to remember though, Holland has been very good at spending money on infrastructure, and the whole country (i think) is below sea level, so they have universal expertise. Unfortunately it doesnt quite work like that in the UK, remember the Ennerdale tunnel?