I loved you elevator pitch. It was visually striking and you spoke clearly and articulately. Your elevator pitch clearly explained your proposed new direction for Trello. I think that you were on to something when you chose to work with an already successful company. I think you are right when you say it will be easier to get VC funding when you are working with experienced and successful people.
I loved your elevator pitch so much that I would have like to see your venture pitch with some audio and slide shows. You are a great public speaker: calm, clear, concise and well informed. You can capitalize on that in your venture pitch.
When I try to put myself in the shoes of an investor, I am concerned that this is a lot of money for something that people can already get for little or no cost. I would spend a little more time giving some specific examples or details about how people get frustrated by spending too much time learning how to use the tools that are supposed to make life easier. I love stories and I would be captivated by a one minute narrative at the beginning of your venture pitch about how the current situation is not working.