Very interesting project. I've also made use of that Shape2SQL program.
I find that a lot of the shape files available are way too detailed for most practical mapping purposes. Loading a few hundred megabyte shape file into SSRS makes for a very slow report.
I am wondering about the financial problems. I'm not sure how it works in the UK but I know in Australia you can get a business number for your organisation and register it as a not-for-profit or charity. If you use a tax agent there is a fee but if you apply directly with the government then there is no fee.
You could also register for tax deductible donations which might encourage people to donate to your "stop food waste" charity.
I think there is a lot of value in what you are trying to do here, not just as an excercise for you to learn Azure but that this can actually work. If you set up a basic wordpress website for this and set up a kickstarter account people would definitely donate to help with the setup and ongoing costs. I would!
These numbers on kickstarter success & failure rates are quite interesting http://www.appsblogger.com/kickstarter-infographic/