Some questions about commercial license.

I'm new here,

and I wanted to know if is it okay,

for example to:

Start a project with free/personal version of C2.

Then request funds con kickstarter.com,

then with those funds buy the commercial version of C2.

And finally release the final product with commercial license?

[Disclaimer: I don't work for Scirra, so this is all speculation based on what I know of their policy]

That sounds perfectly reasonable. Even if the Kickstarter campaign makes you more than $2500, it's not really a C2 game that's made you that money, but the promise of a C2 game. Of course, once you release it you would have to buy the business licence.