Well, here is a suggestion and also a feature request.
I would like to be able to pay-off the bonds i've made, i have now 40 million and my credit rating still 'CC' cause i made alot of bonds, and i could just pay for them so my credit rating could improve a bit.
There is not alot of explanations on the game page so i did discover by myself that having all bonds available is really bad if your going to release planes. And that is a pain in the ass, we should be able to undo our acts, even if we pay more money than we got