WiFi network advice needed

[mds54]

I am completely ignorant of the WiFi configuration and purpose on this phone. Can anyone help?
1) I have an unlimited data plan. Should I care about using WiFi at all?
2) If I have a 4G/3G signal loss, will WiFi automatically kick in to sustain a signal?
3) I currently have no WiFi networks attached, and a scan returns nothing.
Should I be attaching WiFi networks manually. If so, how?
4) Should I just allow my battery optimizer app to disable WiFi?

 

[pool_shark]

Unlimited data will be throttled for the top 5% of users, so why risk it if you have wifi?

Wifi does not automatically connect if you lose a data signal, especially if wifi is not accessible, but if you have wifi on and you're near a known access point it will connect, 3,4G is irrelevant in that instance.

If you're near an access point the scan should find it unless the ssid is hidden. You will still need to be able to access it with a password if it's secured, and if it is using mac address filtering, yours will need to be allowed.

You can turn wifi on/off at will.