A: You can maintain Holiday list via menu "Settings > Holiday". The saved holiday will be shown on your calendar then.
A: There is no time limit on the trial version.
A: Yes. You can use different color for the text entry. Simply highlight the text and choose the text color.
A: You can change the PDF properties in menu "Settings > PDF Properties". You can set "Allow Copy", "Allow Edit", "Allow Print" and also the title, subject keywords, etc.