I have to agree with others and you should likely walk away if your group isn't willing to repurpose and focus on smaller scoped projects before trying to do something that sounds to be quite large.  It sounds like you have some serious project management issues that need to be addressed, and it's unfortunate some of you sunk a fair bit of money into a venture that sounds to have already started on fairly shaky ground.  the better thing to do would have been to start small and make sure your team worked well together and had a good pipeline for creating games, hoping into a large scale project is a sure fire way to fail, as you are finding out now.

I personally would not continue with this group as it stands, something needs to change or you will most likely hit a brick wall again.

Never used Spine but it looks good.

I wouldnt be surprised if Blender could do it, but then again I doubt it would be as streamlined as a dedicated package.   If you are comfortable with Spine 2D then stick with it. 

And don't worry about the price - so long as you aren't going for the full-blown Enterprise edition.  Go for Essentials for now, and then upgrade to Professional later on.

From a professional point of view, being paid should be the first priority. If you have no control and you are sure the project won't be profitable, it's time to let the more optimistic members of this hopeless team fail without you, and get a paid job.

Consider the money you invested as the cost of learning game art animation etc. and acquiring valuable experience about teams, projects and people; it's clear from what you write that the price of wisdom could have been much worse.