PoE+ Gigabit Ethernet Plus Switch

I have not yet purchased this device, but I am contemplating doing so.

I have downloaded the manual, and I've searched through it to answer one very important question.

If, through ignorance, carelessness, or stupidity, a person were to plug an ethernet cable from a computer, into a PoE  powered connection, would there be any damage?  I quote from page 81 of the manual:

6. On the SETTING menu, open the menu for the port number.
The port settings display.
7. Click the EDIT button.
8. From the Port Power menu, select one of the following options:
• Enable: The port’s capacity to deliver power is enabled. This is the default setting.
• Disable: The port’s capacity to deliver power is disabled.

This leads me to believe that I can turn power OFF on 1 or more ports, and use that port as a standard ethernet, with no damage to any devices involved.  But, what if I then plug another device into another port, without disabling the power on that port?

I believe that I read somewhere that a PoE switch queries newly connected devices, to establish power requirements.  However, I'm not certain how that works.  If someone plugs in a laptop that needs no power, will the device just be assigned an IP address, and work just like any unpowered ethernet connection?  Or, might something melt down somewhere?

Needless to say, if I permitted someone to slag a device costing $1000 up to maybe $5000, I would be very unpopular for a long time to come!  I could build a secure, locked enclosure to put the switch into, but that may prove awkward, and unsightly, again making me unpopular.

Thanks for any help!