If location service is off, can I still use Find my iPhone?

It may be that the battery on your controller has failed. Many repair shops can replace the battery for you. Or, if you are familiar with electronic repair, you can...

No, you cannot use cardboard because that will not fold. If it rips a bit, then it should be fine, but if it's larger than about 1/8 of the length...

The payment is supposed to have reached the service place on or before the due date.

You can but don't wait too long or you'll lose your number. Maybe three days maximum, then you may have to start a new account and get a different number...

This will happen if the paper you are using is too small so you should use a bigger piece of paper.

It may be that you're in a rural area far from any cell towers, there could be no SIM card in the phone, or you could have a SIM card...

No, when turning off your location on an iPhone, your friends do not receive a notification. However, it will show the last known location to them if they decide to...

When you turn your phone back on, location services should automatically be activated. This varies depending on your IOS version.

If you tell them, then yes. But they can't if you don't tell them. If they ask, leave.