All the arguments you make were trotted out to justify the waste of money that is Sheffield / Doncaster / Finningley. Sheffield has a bigger population in its catchment than Leeds anyway and look what happened. It's not much further than LGW is from London. The answer is better and more efficient surface links, not lots of small inefficient airports all over the place.
I think your proposition is more to do with injured civic pride or the painful realization that LBA is only ever going to be a bit part player in the UK air travel business.
I'm waiting for someone to be the first to say the universal 'People from here DESERVE a better airport' - often said - but it's meaningless I'm afraid.