#1,2, and 7: Yes. The others: not so much. When it matures (jQuery) perhaps worrying about branding is in order. But if you are spending your hours making a tool for me to freely use, I'm ok if your design isn't so pretty. And if you don't want to spend much time on Twitter. And ...
I don't think the issue is as much about design as it is about seriousness. Having a homepage for the project, spending some time or money on design and reaching out to the community shows you're committed to the project which will get others to commit. That's the best insurance a user can get against the project being completely abandoned one day. As someone whose tried to use open source whenever possible I can tel…
I'd say using a commercial component that's been left for dead is much worse.