This is my favorite question so far! Thanks for your willingness to get involved. Yes, everything you mentioned is appreciated. We would love for you to help us get the word out there. Blog, speak at user groups and conferences, tweet, etc. If you write a cool post on Aurelia or build a neat sample app, let us know and we'll tweet or blog. Help with the docs is always appreciated. We have an open issue on the documentation repo that is tracking the articles we want to write. If you see something there that interests you, let us know and we'll help you to write it. Every author gets credit in the docs, so it's great for you personally as well.
Of course, submitting issues, and helping us fix bugs is always good. But, it need not be anything that technical, if you aren't comfortable. The things you've listed above are a huge way to help us and the community.