Hi Pascal, The way I would approach is that publish the property of the list to the dashboard next to the create button. So after the item is created the user could enter the other details for the item. The Boolean property could also be published. This approach would be for user to input the value manually..And to automatically populate the value you have to write a formula for the property based on the your business rules... Hope this helps to answers your questions..
Given the limited functionality of the creation function, I don't think we would be able auto populate more items.
One other way would be to create a module with line items similar to your list properties, applied with the same list. Then, create a data import process to populate the list properties using this new module as i/p, In this way, it helps to control the entry of the property fields bit more. And populate the data with an extra button to run the data import process.
It's not perfect ou a UI point of view as i have several button (one to create the project, one to "process" and set up the property values, on to open the dashboard to view project data) but in the end i have what i want.