Kickstarter is only open to US residents. I don't believe ol' British Scirra will be able to claim funds from a Kickstarter project. Try Indiegogo if you really want to.
Sorry but kickstarter is a worldwide website, developers can run projects from anywhere in the world. It is natural that the majority come from america but there are many funding projects on their from the uk, china and europe among others.
The recent FTLGame success shows that not only are non US projects possible but they can be successful.
That being said though I wouldnt be offended by scirra asking for donations for the project but i do agree that in this stage of development it wouldnt make sense. Most kickstarter projects are for items that are not released yet or are not in a released state.
My personal recommendation would be to change your pricing policy of the business license from $365 for the programme to $365 per game that exxceeds the revenue level. And then add a 4th license level for corporate or something which would cost thousands perhaps but would cover every game a studio might make in the future.
This way every time a developer makes a game that exceeds the $5,000 in profit scirra would get another business license purchased. And bigger companies that use scirra would be paying the larger cost of the corporate license to license any game they make etc.
My 2 cents: it also is inline with similar programs which have a lot less features, a lot less support and are nowhere near as user friendly.