Some questions (p2p, funds not showing up in balance, GPU mining, wallet.dat backup)

First of all: thanks for providing near failsafe instructions on how to install Zcash on Linux operating systems. I managed to install it at ease on my notebook running Linux Mint. (Used this device for a long time to also run my Tor node.)

But despite being able to run my node, I’m facing some trouble.

(1) Zcash is P2P in blockchain distribution, right? So why don’t I have any outgoing traffic on my line? All ports are open (exposed host) and only very little traffic is generated by Zcash.

(2a) I mined some Zcash on with my AMD Fury X setup and according to my payout statistics, I already recived some ZEC to the z address I provided. However, this payout is not showing up on my balance when requesting my statistics with “./src/zcash-cli getinfo”. And yes, I verifyed with “./src/zcash-cli z_listaddresses” that the z address is in my wallet. Any suggestions?

(2b) So I thought this might be an indexing problem and tried to run Zcash with the reindexing parameter (“./src/zcashd -reindex”). But it didn’t help. The only message I got from Zcash was “Activating best chain” for hours, so I stoped it by pressing CTRL+C. Then I deleted the “chainstate” and “blocks” folders from the “~/.zcash” dir, but it didn’t help either. Any suggestions?

(2c) Is there a working blockchain explorer for the Zcash mainnet? I want to verify actually sent out the funds to me.

(3) When I started mining Zcash via with the Genoils Zcash miner for AMD cards, the miner frequently crashed. This problem solved itself without any input from my side. Does anyone know why?

(4) The wallet.dat file in the ~/.zcash dir is the file I want to backup, right? Just as with Bitcoin?