Fiber is super easy too. Fiber patch cables are extremely durable and don’t have glass in them. Very durable.

Cheap too!

I’d do the UBIQUITI Aggregation switch. 8 10 gig sfp+ ports. You do need to go fiber though as you can only use 4 ports if you use copper due to heat. Forget 2.5, it’s a weird speed. Just do 10

Need more info.

Typically 100mb limit indicated a bad cable or a device in the line that only supports 100mb

Just go get a better router from a store that allows returns. If it fixes your problem, great. If not, return it and harass your isp

Set up a vpn on ur router and use rdp