If you do not have any sensitive details in that account, it is better forget it. FB will never care and due to their new spam account closure policies, they are removing many accounts which are inactive for a while.
Do you mean you want to access another computer on your LAN remotely? You can use Telnet to do it or you need to install third party applications. I used TeamViewer for it.
Can you make calls to BSNL customer support using the locked number? If you can't, you must visit nearest BSNL customer service center and explain them the issue. Or you may ask for SIM change.
You can activate the battery saver option on your phone. I always use to extend the battery charge in my travels. But it will not help you save the battery charge for weeks. So as the hang-the-9 suggests, you should go for normal 2g phones for the prolonged battery charge.
I always purchase middle price range phones. So even if the Phone gets issues over time, it won't hurt my purse very much. For your case, I suggest you go for Android Phones. Apple is too costly.
Have you changed any settings in File manager? I once faced this issue due to the file manager installed on the phone.
I had to browse through the file manager to get that files back. I tried it.
https://www.corenetworkz.com/2017/09/access-transfer-downloaded-hotstar.html