When an issue has an estimated time of, for example, 4 days ... you can still resize it to 1 day. Is there a way to prevent that?

Similarly, as the remaining estimated increases / decreases in JIRA, ideally that information would be automatically displayed in the calendar timeline as well.

Finally, from a visual standpoint, it would be nice to see colors associated with various statuses (i.e. green = resolved, red = open, etc).