I think I have mapped out a way for the Multi-domain plugin to work with subfolders. I hope it will cover all the known issues with Multi-domain plugin usage with subfolders.
First, as I intend to have custom post types, which I will implement via wp-types plugin), I will implement a network-wide permalink structure such as
for all post types. (Or maybe a different ordering will given better performance.) I think the only thing custom is the insertion of %posttype into the permalink.
I am ok if the URL turns out to be long. I just do not want a user to be able to make any kind of posting that is just domain/%postname as that might very well lead to a URL conflict. (I will install an URL shortener for individual user use and see how that goes.)
I will still try to make rewrite rules for certain landing pages form the network admin account, i.e., such that URLs like domain/pagename still work at least for the network admin.
I think as long as any_sitename <> "category" <> "tag" <> any_page name including the BP pages <> "blog" <> any_custom_post_type <> any_group_name <> any_forum_name then there should be be no URL clashes.
I am ok with the insertion of the word "blog" in the posts of the admin accounts.
I am ok with the default BP pages, i.e., /members, /groups, /blogs, /activity, /forums, etc. I will put these words on the blacklist for both site and user registration. "blog", "category" and "tag" will of course be blacklisted as well, and they all will be mutually excluded from each other.
Second, I will set user roles (via user role edit plugin or hard-wiring in the code) such that no one but a network administrator can change the permalink structure.
In this particular network for the most part it will be sitename=username=author, that is, it will be one-user-one-site, as as far a the permalink is concerned that equals author as well.
Only the network admin account will have more than one user. A user will be the admin of their own site in terms of content management, but there will be some executive functions re: themes and plugins that siteadmins will not be able to do. Rather they will be reserved for the network admin.
As this is a organizational member benefit, the network admin will handle the creation of accounts. That is, there will be no mechanism for people to register for the site on their own. So in addition to the blacklist there will be human intervention.
Do you think this will cover all the known issues with Multi-domain plugin usage with subfolders?