1) Whether a portrait or Canvas I always receive the same email: can we do a different email depending on the case?
Nope, at best you can override it to make it more generic using CBs language overrides functionality shown below. Avatar, Image, and Canvas fields all share the same code so they share the same email as well. We'll improve this later likely in CB 3.0 when we completely redo all the field code.
www.joomlapolis.com/blog/kyle/18701-language-overrides-have-arrived
2) Other recent and more annoying problem: To search for box 1, In the filtering in the list of users, the result and now always blank looking "Avatar pending" or "Canvas waiting" So it is unable to find the user to approve the change, how to do now? can be a bug?
Use the CB Workflows module included with CB to quickly access pending approval images or create a Joomla menu item with menu type Community Builder > Moderate Images. You do not need to search users to find users with pending images as the image approval page will show you only those images pending approve.