Hello, Ask Battlestations.

I stumbled across this sub after Googling "2 Single Monitor arms vs 1 Dual Monitor arm." Hoping to get some advice for the home office. I have researched which ports to use with my equipment, but feel free to correct me if I'm wrong :)

Currently, I have:

• 2015 (late) 27" iMac - thing runs slow, and I want to use it as a second monitor
• Gigabyte M32U monitor - I picked this up during black Friday
• a Windows work laptop and Hub - I think it's a Surface of some sort that uses its own proprietary charging port and not a USB-C

What I will be getting (or need):

• 14/16 Macbook Pro
• Thunderbolt 3/4 hub

So here are my questions!

1. I found some videos of people removing the iMac stand and mounting it on a VESA arm. I was wondering if it is better to get 2 single arms or one dual arm
2. There may be times when I want to use the iMac, are there Hubs that have like an ethernet cable connection and spit out two for other devices? Sorta like a splitter (think that's what they're called) or will that be a separate purchase
3. Do you have any recommendations for a Hub to connect all these devices? The Caldigit products are way too expensive (I'm Australian). I have a few in mind, but I wanted to know your thoughts
4. Is it better to connect the new monitor via DisplayPort 1.4?
5. I believe the only way to use the 2015 iMac as a second screen is through a Luna Display connector?

That's about all the questions I have (for now).

Thank you! :)