The reason you don't see a PoodLL widgets icon is probably because it is not selected in the list of icons to show.
See Step 5 on the Getting Started page, for how to do that.
If you are using TinyMCE then there is no PoodLL widgets dialog. Until we write one of those you will have to either:
- make the poodll filter strings by hand
- create a special Moodle user for Atto
Regarding ii), you can set the preferred editor per user in their user preferences. So you would create a user with the same access rights as your own, and set their editor preference to "atto." Then when you need to add some widgets, log in as that user to do so.