Add choice income line and checked boxes

Hello, I need to know if it is possible to add a choice in the "sales_stage_dom" drop-down list, on the "income line" module.

Would it be possible to add the choice "à facturer" with a probability percentage of 100% on the drop-down list sales-stage-dom on the field " sales-stage"?

Another thing, for each line that is automatically generated, is it possible that, if the "renewable" box is checked, the default choice is "à facturer"?

Finally, we have created "Indice SYNTEC", "Mandat SEPA" and "Chorus" checkboxes, if these boxes are checked, can they be checked automatically also on the lines which are automatically generated?

Thank you