We have set things up as a single document for every project and each project has a to do list. My wish would be a dropdown in a new to do item that would allow you to select the project and then the to do associated with the project. Or some other way to select the project and task that a timeline element is associated with. Same goes with the milestones, it would be great to assign a milestone to a project and the time on the timeline is what it takes for the team to reach that milestone.
My team tries to plan ahead so we'd like to map out all projects on a master timeline to see how busy each staff member is. So I'd also love to assign the number of hours I'd be working on that to-do for each day like Float allows you to do.