Power Cords/ Conditioner/Surge Protectors

Full home surge suppressor, nary a worry. No dynamics sucking boxes.

Also love the suppressor for .45acp. Neighbors have no idea I am shooting targets in my backyard.

From the bottom of your list up.  

1. Of course you want surge protection to protect your investment.  Power conditioners like Shunyata and Audience have surge protection.  
2. Conditioning produced a significant improvement in sound quality in my system.  Power Conditioners remove noise on the power line from electro magnetic interference (EMI) by filtration.   Good power conditioners also remove noise from ground loops and isolate your equipment electrically from each other so noise from a computer module in a streamer does not enter the audio system circuit.  If you live in an area that has a high population/home density or has industry, conditions are recommended.  I have had improvements with both Shunyata and Audience.  The higher end models give the most improvement.  Regeneration is another option which also reduces noise by converting noisy AC to DC and regenerating it to pure sine wave AC.  Regeneration is recommended if you live in an area where there are voltage fluctuations.  For example, I use regeneration in a vacation home in VT but power conditioning in my permanent home in the NY-suburbs (voltage fluctuations vs noisy mains).  Good regenerators have surge protection.  
3. Good power cords prevent EMI from entering the system.  EMI will enter a system at the weakest point - the least shielded point in the system.  Good cables also have low resistance and high conductivity, improving SQ.  I use WyWires Platinum on all equipment.  Each wire brand has its own sound characteristics, so brand is a personal choice.  

Good luck   

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ZeroSurge looks interesting. I like the inductor type protection. I have been using SurgeX equipment for years. I use it on installed pro systems. It has models with remote tun on and off, squencing, and low or high voltage turn off.

@kmcong grounding per se won’t help. You need proper protection circuit. Like this https://www.truecable.com/blogs/cable-academy/when-lightning-strikes-ethernet-data-cable-and-lightning-protection

@jea48 

The surge was caused by a pole mounted transformed that exploded. The pole is about 300 meters from me on the main road I live off of, and "downstream" from the branch that runs behind my house. I am the last house before the fuse on my branch and my neighbors lost electricity. the blown pole was kinda cool, it blew the top right off and it burned until the fire department put it out. 

My computer, server and modem are in different rooms, and had fairly new surge suppressors, so they survived just fine. My printer though was unprotected and was also a casualty.

Your point about internet is a very good one. I use subnets in my house to isolate IoT devices for security. My 2 channel system uses fiber ethernet, so it is safe from internet spikes.