I'm a fan of the concept and I hope the project goes well, but I'm not going to hold my breath, nor am I likely to contribute any cash.
For starters, subscription model. Zardnaar and others touched on the biggest issue, but to put it in specific words: I dislike a model that requires me to pay regardless of whether or not I'm using a product. There were a couple of times during DDI that I got involved in other activities that caused me to skip my 4E game for a few months at a time, and it was just too much of a pain in the butt to figure out how to cancel the subscription and then renew it when I needed it, so I gritted my teeth and kept paying because I knew I'd need it later. If you have to go with a subscription, at least consider using a 'time bank' where I can pay in for the amount of time I think I need, then pay in for more if it turns out I need more; that way I can leave the bank empty while I'm directing a play or some such and fill it back up when I'm ready for more gaming. (It's not dissimilar to the way cellular data subscription works on my iPad, if you want a concrete example of the concept.)
Next, Pathfinder. I can see why you'd believe that Pathfinder is the next logical step after not being able to implement licensed 5E, but Pathfinder isn't a new market and despite the cool factor of the project, the folks who are most likely going to want to support you will have to weigh that support against any costs they've put into an existing product. I myself dropped $80 on HeroLab licenses for Pathfinder to prep for a new game a friend is running; some significant portion of that might have gone to your Kickstarter if you were getting ready for Pathfinder three months ago, but now that's money that's committed; tossing cash into a Kickstarter for a product that might not replace the tool I'm currently using (and that I don't have to keep paying for as long as I don't add new licenses) seems like a risky investment.
Lastly, and in a more philosophical sense, I'm not sure that high-end software development processes make a good fit with traditional tabletop RPGs. I'm sure you've chatted with a lot of DMs over the past few years; have you noticed how much like FOSS* developers they sound? ("I don't like that rule, so I made up my own." "I've been using a homebrew hybrid of FATE and 3.5 D&D for the past few years, and it seems to be doing OK." "I need a few more sessions to tweak before my mass battles module is ready for beta testing.") It's great that you recognize that DMs want flexibility and the ability to deliver story and rules content in interesting ways; it's weird that you seem to believe that your product will be the one to overcome the cheap-as-free way things like that have gone for decades. If you're really interested in the project surviving, I'd think the absence of a licensed partner would have given you the perfect opportunity to go open-source and establish yourself as the best-of-breed code available for the task. Instead, it seems your dream is more about making a living off of your work, which is admirable, but might not be actually workable.
Best wishes.
* - FOSS = Free and Open Source Software, for those who may not have encountered the acronym before.
