No, due to different reasons.
First, the network is always in flux, nodes are appearing and disappearing, and connections are even more dynamic, so even if there were an API you could use to ask a node for its connections, that information would be outdated quickly.
Second, privacy is part of the reason why crypto currencies exist. Divulging the list of ...
From my understanding, the difficulty of the network will still keep increasing when the "target" block is mined, regardless of the number of miners (yes?)
The difficulty readjusts every 2016 blocks, based on the average time taken to mine the previous 2016 blocks. If the average is less than 10 minutes, the difficulty goes up. If greater than 10 ...
Someone wrote a Bitcoin protocol decoder for Wireshark, several years ago. I assume it was included in the Wireshark distribution.
Wireshark simply knows about the Bitcoin protocol. There is no magic involved.