Specifying node & regions

Not sure how difficult this request is, but it would be great to be able to indicate by path where you want the block to be displayed directly when creating the node.

I think this is a very specific feature that is out of the scope of the module. What you can do is to implement a custom module that alters the node form and set the value of the region accordingly with your requirements.

It would also be useful to be able to restrict in which region the block could placed in by role. For example, staff can only put node as block nodes in the right sidebar.

This may be a valuable feature for real use cases. One question, if a user have more than one role, how can we handle this, including the union of all the regions available for each of its roles? thoughts ???

One question, if a user have more than one role, how can we handle this, including the union of all the regions available for each of its roles?

Following this issue: maybe module "role weights" gives a part of the answer: http://drupal.org/project/role_weights

Suppose a user have role A and role B. Users with role A can place blocks on region "left" and region "header", while role B can place blocks on region "left" and "right". So, as the result, the user can place blocks on regions "left", "header", and "right". I think it could work this way.