Default settings for the program or queue

I am a normal user and do not have permissions to add or remove queues. Can I change the settings of the queue (like duplex or input trays)?

Yes, you can change the settings for a particular print queue, and those settings are saved to your home account. You can also change the settings for a single print job.

I changed the settings on the queue, but when my colleague prints to the same queue on the same host, the settings are different than mine. What is wrong?

You have created user settings for that print queue, but if your colleague has not, the system settings are still in effect. Your colleague must open the printer driver and change his or her user settings.

Can I make My Printers my default group?

No.