The website will always have the full text of the rules, however the SRD (which will be released within the next week) will have a more minimal version of the rules and will be the open source core, a PDF that people can freely distribute and share. This SRD will include the core mechanics, feats, banes, boons, perks, and flaws. However, certain non-essential components, like the GM advice section, will not be in the SRD -- only the website, PDF, and Hardback books.
So, if you're OK with reading boring text that is not beautifully laid out or illustrated, then yes you can get what you need from the website.
The SRD itself will probably prove very useful both as a quick reference PDF during gameplay in addition to the more targeted focus of providing content that 3rd Party Publishers are allowed to re-use under the soon-to-be-revealed "Open Legend Community License".