Finder constantly not responding/freezing My system

I've read about a dozen similar questions to this. I'm running a 13" retina MacBook Pro and using El Capitan 10.11.6.

System is generally stable.

Model Name: MacBook Pro
  Model Identifier: MacBookPro11,1
  Processor Name:   Intel Core i7
  Processor Speed:  2.8 GHz
  Number of Processors: 1
  Total Number of Cores:    2
  L2 Cache (per Core):  256 KB
  L3 Cache: 4 MB
  Memory:   16 GB
  Boot ROM Version: MBP111.0142.B00
  SMC Version (system): 2.16f68


The issue

Annoyingly the same time I went abroad for several months in a region with no Mac stores without taking several flights and unreliable internet access, the system has basically stopped working.

Well, anything to do with Finder doesn't work. Any time you open a new tab or window it freezes (goes Not Responding) in Activity Monitor and Dock. I get spinning beach ball for 10+ minutes but it usually recovers eventually.

Relaunching or Force Quitting doesn't help at all. There is no CPU spike or anything like that.

Other apps freeze/crash/go Not Responding on start too and never seem to recover. Every single time I try to use BetterTouchTools, TextExpander, Excel or uTorrent they cannot run. I suspect it is related to the more fundamental Finder issue. Weirdly, Word will run fine as will Transmission.

Just tried installing Commander One as an alternative. Hang immediately on opening too.

I put some crashlogs on Dropbox if somebody wants to have a look: CommanderOne, Excel, uTorrent.

What I've tried


booting into safe mode to reset Finder settings
resetting SMC
HDD benchmarks and SMART info is fine
killing Google Drive
Nothing obvious in system.log
mv ~/L*/S*/*finder.savedState Desktop followed by killall Finder


Edit: also tried restoring from several Time Machine backups as far back as November and the symptoms persist. Wtf is this????

HALP?!
How odd. But I solved it.

Of course, I lost about half my files with the system restores through Time Machine before I worked it out. 

nohillside ♦ pretty much got it spot on. It was me using autofs to mount network shares. Quite why a network share going down or being unavailable means that the entire system is unusable is beyond me. It fact, thinking about it, it's utterly insane.

I wonder if now I have to write some really hacky script to automatically disable autofs if it can't connect to the server a few times in a row.

Another thing that I fear will remain an eternal mystery is why various other apps completely locked up and failed to start. Why TextExpander and BetterTouchTool? Why any file manager? Why Excel but not Word?!

TL;DR - how do I fix it?

Simply deleted the auto_nas file with:

$ sudo nano /etc/auto_nas


I kept the line in /etc/auto_master