I cant see Bonaire being the major hub for KLM in the Caribbean as all the infrastructure ,refeineries, workforce etc are close by in Curacao. Bonaire is also not cabable of taking KLM's large jets.
Bonaire would be a great place to live if you are into Scuba or sailing and you are happy to live within a very small community.
Not a lush green Island, desalinisation is the order of the day in this part of the Caribs.
I lived in Curacao for five years and did not find it too expensive but of course it all depends on your package.