DataAssist creates and uses Dreamweaver Recordsets.
The DataAssist wizard will not not create the complex type of recordsets you mention, but the pages can be edited after they have been created and you can update the recordsets.
For the complex scenarios you are mentioning, I don't think you would be using the Wizards much, but would be creating your own recordsets and forms and using the individual server behaviors for inserting, updating or deleting.
There are server behaviors for single record inserts, updates and deletes as well as multiple insert updates and deletes.
There is also a manage relational table behavior for managing linking tables.
These can be put together in various ways to create complex data management applications, for example you can use 2 single record inserts on the same page to create a form that inserts to 2 tables.
The data assist behaviors do not use data transactions, they use standard inserts and updates.
