1) Screenshots of the features you describe below

2) A section that shows all the members you already have (show their profile pictures)

3) A new video. Make it shorter, more punchy, put in some sound, and some better animation. I suggest that you look at Wistia's video: http://wistia.com. I took inspiration from their video, because it seemed like anyone with no background in video editing/design can come up with a Wistia-like introductory video. But it's simple, short, and tells people what they need to know, which is what I like about it.