There are entirely too many Modal dialog boxes in Illustrator. It would be nice if there were none. Everything that currently pops up and steals focus (completely obscuring everything behind it) should be done in a "settings panel" that can be opened or closed as necessary.

For example, there is nothing so urgent about the line tool that it should require a modal dialog box to open. If I want to configure the settings, they should appear in a panel called "settings" and I should be able to change them easily without having to stop everything, fill out the form, press apply just to come back and do it again in a minute or two.

Realistically, 99% of the modal dialogs Illustrator currently uses are not needed if you just had a Settings Panel that provided access to the tool settings dynamically without stopping your work.