Building stuff is always impressive so well done on that. For me it feels a bit like you are saying the audience for this is 'people who want their friends to pay for them to do stuff'? My question would be if I know these people socially, why do I need a website to handle this?

As others have said, I think there are fairly clear mental models for exchanging money: charity or jobs. At the moment, what you seem to be describing is a jobs model, but with added complications such as a campaign and a set end date?. Its not clear me what value I get as a person paying things as a result of these added steps, so why would I use this over another market place?