It’s the real world folks. Some people are negative, some positive, Some are dreamers, others realists. As much of a party-pooper as Alvaro might appear to be, his general comments hold a lot of water.
You must have a story - and it must be solid.
You must pre-produce everything. Get it all worked out the old way - on paper.
Don’t start making and submitting ANY models to a project that doesn’t have more than two frames of story board or any finalised style-sheets for characters or sets. The models are distractions and cause problems if they don’t fit the style. It’s difficult to keep members if you suddenly start rejecting stuff that was “cool” a few weeks before.
Since it’s likely no one on the team is an experienced producer/director - it would be wise to produce a semi-animated storyboard quite early on and a low-poly animatic once the story board is accepted. The animatic should be a final test of camera angles and edits. The storyboard is the Bible - the animatic is God himself (no religious offence intended). If the movie doesn’t work well at this stage then no amount of cute characters, wild cars, funky walk-cycles, bump-mapping, sculpting, ray-traced reflections, ambient occlusion, fluid dynamics or soft-bodies is going to rescue it.
Once the animatic is accepted, THEN make the characters come to life with real movements (walk-cycles and stuff) and materials, textures and lighting. Why waste days or weeks on walk cycles and other actions if there’s no guarantee that character will even be in view in the final cut? (Sure, experiment with action styles for characters but don’t waste time committing to the unknown). If someone on the team is an experienced producer then they’ll presumably insist on this approach anyway (Ice Age 1 collector’s edition DVD gives a good overview of storyboard to final comp workflow)
Oh, and one more thing - abandon any thoughts of ray tracing a highly-complex set of scenes unless you have ready access to a major renderfarm. Learn buffer lighting - and learn it well - so all the hard work will actually make it to video format.
Like most things in life, it’s the really boring up-front preparation that makes the final production enjoyable, worthwhile and more likely to succeed. There’s a big brick wall waiting ahead. If you’re careful, you can build a platform that’ll help you get over it - but if you ignore the scaffolding and just run flat-out forward, you’ll just smack into it. But at least it was a fast trip 
(I do not have direct experience in film production or animation production but have worked on TV ads, film sets, amateur theatre and a bunch of completely unrelated things like spray-painting vehicles, painting signs, commercial illustrations and landscape painting and in all cases the preparation is what determines the end result. None of it happens as a result of youthful exuberance or happy thoughts).
Now, having said that, let me also say that working on something like this can be a great experience and, on a personal level for each member, if experience is the only thing that comes from it, it was still a worthwhile exercise. I learned more Blender in a few weeks working on the Crosswalk than I would probably have learned in a year without it.
One last suggestion: Don’t assume anyone will remain with the project long-term unless you’ve got them signed up to a contract. You can wish it and hope it but don’t assume it.
Good luck.