GAE NDB Confused about Models and duplicating attributes

I'm trying to learn Google App Engine's NDB and I'm confused about the structure of models.

My situation is similar to a CMS platform with Post Types (like in WordPress), so I have "Blogs" and "Pages". All of these Post Types require the same set of attributes: Parent, Name, Slug, Template, Content, Status, and Date.

So far, I gather that I need to create a Model for these like this:

class Post(ndb.Expando):
    parent = ndb.StringProperty()
    name = ndb.StringProperty()
    slug = ndb.StringProperty()
    template = ndb.StringProperty()
    content = ndb.StringProperty(indexed=False)
    status = ndb.StringProperty()
    date = ndb.DateTimeProperty(auto_now_add=True)

(I'm using Expando because I will be adding "unknown" attributes in my application)

But with this structure, all of my posts (in every Post Type) will be within the same "kind", so queries will take longer (if I'm not mistaken).

• How can I create many Models (kinds) with the same attributes?
• Do I copy & paste the above Model under different class names?
• Is it possible to create new Models dynamically (similar to "Custom Post Types" in WordPress)? Does it work if I use ndb.Key('Blog', blogid) instead of declaring a Model?
• Do I create a Model called class PostType(ndb.Model) that stores the "Post Types" and give them ancestors of Posts? (If I'm not mistaken, this would cause problems because updating a Post would "lock" the entire ancestor tree for a second or so)

My primary goal is efficiency. Thanks!