Wagtail has a good tutorial to get you started (
http://docs.wagtail.io/en/latest/getting_started/tutorial.ht...) and has good enough documentation (that I think would need some improvements). I know it seems a bit overwhelming to start a new project but you can try to learn from existing ones that are available for example the good-old wagtaildemo:
https://github.com/wagtail/wagtaildemo, the better-wagtail-demo:
https://github.com/wagtail/bakerydemo and of course the RCA (
https://www.rca.ac.uk) website
https://github.com/torchbox/verdant-rca/ (be careful this is a huge project that uses a little old version of wagtail - 1.6 but most base things are the same in later versions)
Now, for answering your questions I think that Stackoverflow should be fine for asking, most (if not all) questions are answered there (I know that most wagtail developers monitor SO for new questions and answer them promptly). Don't be discouraged by the small volume of questions -- the only problem with SO is that some questions (the more open ones, for example those discussing architecture) are not considered proper for this site and are closed so you should use the mailing list for that.
For the StreamField I totally agree that it rocks however keep in mind that you'll still need to add a model-per-content-type (maybe not so many content types but you will definitely need more than one content type) - I think that the StreamField offers more freedom to the hands of the content editors, using it they can mix and match their content to the page and not follow specific patterns that the developers have decided.
Finally, concerning the deviation from views, don't be alarmed. Wagtail uses a concept called Page (probably should've been called PageType or WagtailContentType but anyway) which is a mixture between a Model and a class based view. So you create your own subclass of pages which are Articles, NewsItems, Events etc. The important thing is that most functionality of CBVs is inherited when serving each Page type so you can override the various class methods like get_context (to add specific things to the context of a page), get_template (to change the template of a page type), serve (to have full control on serving the page) etc. Also you can add mixins similar to CBVs so that many of your Pages will share some functionality.
I recommend you try wagtail and I think that you'll like it!