Let's say I want to start a completely transparent business and want to make the financials available online. As an example, let's say I want to start a recording label. I would contract studios, producers, publicists, engineers, session artists, etc. and pay them all with Bitcoin. Each contractor and their sub-contractors would need to be traceable through some sort of spreadsheet. It would be nice if there was a Bitcoin enabled spreadsheet capable of creating raw transactions. Perhaps this can be done manually. The spreadsheet would need to create a tree that follows the payments and credits each and every person with their unique IDs.
Can something like this be done with Excel?
PHP/MySQL is your answer IMO. But the tree thing in your requirement is very dangerous with big data. To properly maintain a tree with big data u need to move towards NoSQL as DB choice ...again my opinion. Views differ in terms of architecture.