Redmine

I searched around a bit but couldn't identify whether any of the existing plugins that improve the calendar are capable of the following:

• Define how many hours per day and which days of the week certain people work.
• Drag & drop an issue from the pool of issues into a person's calendar to assign it to them.
• If you drop the issue in between others, it automatically pushes away / shifts / delays the issues that come after that point.
• You can change the estimated time needed for an issue (especially while working on it) and again, this automatically shifts/delays later entries in accordance.

Does anyone know if all this can be done with a plugin or some combination of plugins? Thanks in advance!