I think we are getting too off topic here so maybe make a seperate post in here asking how to tinker with selfhosting, dns, tinkering etc and you can have multiple people’s inputs.

It can be a good idea to mentatlly seperate your router needs with you 2.5G speeds and WiFi needs, they dont have to live on the same device. For you private lan you need a router so you can hide and control your devices behind NAT and firewall. For that I’d just recommended one of the small hap or hax devices that suits your needs for routing, and/or wifi. If you want to be fancy the RB9005U could maybe work with your switching need as well.

You don’t need Vlan. I believe it is not what you think it is. Vlan is if you want to segregated your own lan int to different independent lans with various firewall rules.

All you need for your dorm is NAT. But for the love of god make sure that you dont connect your lan with the dorm lan or your DHCP server will start handing out IP’s to everyone else in your dorm and it will crash the dorm router. The ethernet jack in the wall of your dorm (I assume that’s how it works for you) needs to go to the WAN port of the router. But bare in mind on mikrotik you can configure the WAN port to be any physical port you want, but with default config it is port 1.

I have done this before as well when living in a dorm where wifi was shit so i did my own little setup in my room so I could stream to Crome cast etc on my own trusted lan. Get a small router with support for wire Guard vpn (i love mikrotik for this) and you have an easy way to tunnel out for all your devices.

I have a raspberry pi with a cheap 5TB usb drive at my parents house that boots up once a week and pulls a backup. I use rsnapshot to create incremental updates that takes up every little space and is easy to manage. I have the drive accessible with smb should I ever need to pull a copy from there. It’s super slow but that doesn’t matter for an off-site backup and it is super cheap

Edit: I should maybe add for future readers that cheap does not mean cheap quality but cheap relative to the amount af TB you get per dollar. I use a WD shingled drive wich is quality drive but cheap and slow af. But it doesnt matter because the internet connection is the bottleneck anyway.