If you really want to validate your market, you should remove the Developer and Pro Tier commitments. Stick to your original blog post of securing 10,000 backers like you noted in your original proposal. Right now, your Kickstarter campaign is designed in a way that may lead to false positives.

The barriers to entry as a messaging infrastructure service play are low. Even if your platform is reliable and stable, you will be quickly commoditized to competing on price which is not a sustainable business model.