You're absolutely right, but this is well covered ground when dealing with smaller software vendors in a B2B environment. Source code escrow (http://en.wikipedia.org/wiki/Source_code_escrow) is something we would often do when I worked for a company that sold ERP software. The basics of the idea are to give good answers to all the questions you put at the top of your post about what happens if the worst happens. A source escrow agreement makes it so that if the company you're buying the software from disappears, you at least have access to the source and will have a shot at not being completely screwed.
Thing is, though, that the source code license isn't really the thing that you're betting on. It's your relationship with the vendor. Your business can be screwed a lot by a business long before the escrow agreement kicks in, and long before they fold.
Being heavily dependent on a software company, at least in ERP type business software, is a lot like marriage. You definitely want to pick the right one, and it's all about the relationship. If the marriage goes bad, it can make your life hellish, even if you do have a pre-nup.
possibly 1 good argument for open source software is that this kind of depedance on 1 other business generally isn't there. most bigger open source projects have people from various companies working on them, so relying on that software is safer cause it doesn't depend on just 1 other company.
having said that, this isn't always the case, but in many situations bigger open source projects that are widey used it is.
Thing is, though, that the source code license isn't really the thing that you're betting on. It's your relationship with the vendor. Your business can be screwed a lot by a business long before the escrow agreement kicks in, and long before they fold.
Being heavily dependent on a software company, at least in ERP type business software, is a lot like marriage. You definitely want to pick the right one, and it's all about the relationship. If the marriage goes bad, it can make your life hellish, even if you do have a pre-nup.