V1 looks like this http://static.tp-link.com/res/down/doc/TL-PA7020_KIT(EU)_V1_UG.pdf V2 http://static.tp-link.com/1910011905_TL-PA7020(KIT)_V2V3_UG.pdf

Is the model number correct? I don't see a TL-PA8035P. But I know that TL-PA8030P support IPv6 but you need to contact tplink support to get the software to enable it.

yeah change the wireless settings may help. Maybe you push the button to clone the wireless settings from your router? Is it why the 2.4G SSID disappeared? If that's the case, reset the powerline...

check the dial number, APN, username and password with Fastweb. If you login the router, go to Network>3G settings, set those info manually. On the other hand, you can also check the firmware version...

First of all need to check your BSNL sim card. just insert it into your phone to test. And you can login the router to check the 3G status, if it's disconnected, then try create a new profile with...

You can find it here http://www.tp-link.com/en/support/3g-comp-list.html?model=TD-W8970