Is it possible to change the default time of 9:00 for reminders in the calender?

it's a bit limited (as far as category), but take a look at the "Mail, Contacts, Calendars" tab in your Settings app. If you scroll all the way down the right-hand side, you will see a line titled "Default Alert Times" (it'll be in the "Calendars" grouping. Pressing on that line will allow you to pick a new default.

Hope this helps.

Marilyn