is there a way to require passcode to shutdown iphone

Why would you say that? There are a myriad of ways to cause the iPhone to go offline which do not involve actually turning the phone off if a thief wants to do that. But, with Find My iPhone, you can set up an executable command to put the device into Lost Mode or to Erase the device, and as soon as it is turned back on and connects to cellular or Wifi, the command is processed.

You also have the last location showing for 24 hours.

So, not sure why you would think it is "useless".

GB

yes you can set a password before turning off. just follow the step Setting > Touch Id and Pass code > set the Pin code. so when you turn it off and want to turn it on you need a pass code.

Cheers

No, sorry but that is not a feature of an iOS device. You can send your request to Apple here: Apple - Feedback

Cheers,

GB

Find my iPhone is not designed to prevent theft.

It may help you locate a lost phone. It will protect your data if used correctly.

But can someone use a stolen iPhone by hacking it.

Not true.

Once you have enabled Find My Phone, this enables Activation Lock. Activation lock is, at this point, unbreakable. The device is useless to anyone who does not know the password, or can produce a proof of purchase. They can not re-use it.

My daughter lost hers and it's been a mont and shows offline.

And it will likely stay that way.

If it is already on then you can't require a passcode to turn it off.