could anyone purchase a .org domain & display false reputation
Anyone can purchase one, but I don't think it implies someone is displaying a false reputation. Maybe I feel that way personally, because I've always known that's been the case. It wasn't the original intention, but neither was .net domain usage. I don't know what a newbie websurfer might feel.
Just as an example, to show it's not legally restricted: There's now a complete website for the fictional foundation that's supposedly behind all the secrets of "The Island" on Lost - and it's a .org site. Perfect for what they're doing, because the fictional foundation is supposed to be non-profit, but if it were legally restricted the show's producers wouldn't be able to do this (and get away with it, that is - they're not exactly keeping a low profile!).
Might not be a bad idea to build something trustworthy ~ something built with the idea of adding value to the WWW and its users, not primarily focused on adding value to your wallet - IF you are going to employ a .Org as your platform.
It's something I've pondered a great deal as I've philosophically explored what to do with the .Orgs for which I'm registrant. The closest I've come to "how to approach the domain" is to focus on the benefits to others in what you build. At the very least endeavor to stay true to the gist of the TLD's mission.
Organizations can be industry organizations and nothing is quite so commercial - whilst not being purely commercial - as an industry organization. That's a somewhat interesting, but I feel fair discernment, one that has drifted in and out of my thinking whilst laboring to design for the near term and long term.