"Safe" personal router use on apartment-wide network

I recently moved into an apartment with internet included in my rent. This was a boon at first, but now I'm feeling limited. To get devices connected (wired or wireless), I have to whitelist the MAC addresses on mycampusnet.com. This is annoying (considering I'm well over the 10 device limit including my roommate's stuff), but what's really driving me mad is that I don't seem to have any semblance of a "local" network.

I've relied heavily on static IPs and port forwarding in the past (accessing NAS and remote desktop) and (as far as I can understand), that functionality is nonexistent without my router set up. Also, as my wired and wireless devices don't always seem to make it onto the same subnet, I'm unable to use any of my iDevices with my Apple TV (I can, however, mirror to no less than four strangers' Apple TVs at any moment, which is a whole other level of discomforting).

I've talked to the head of the apartment complex and she told me that they personally don't have any issue with my using a router, but the provider (CampusConnect) does not currently allow it. Apparently, enough people have put in complaints/requests about the restriction (the apartments are for graduate students and University staff, many of which need to set up things like VPNs for work reasons) to open up some sort of ticket to get the functionality in place, but all the calls I've made to get status updates have been a waste of time.

My question is: If I plugged my router into the apartment network, what would happen? I've been told already that personal routers would "interfere with the wireless" and that they would shut my port down if I used one, but is that a legitimate thing or just something made up that sounds real to keep the average Joe from pushing it further?

I'm guessing there's some way of configuring my router to keep it from disrupting the rest of the network, but it's not something they want to tell me for obvious reasons. Am I right? And if so, what are the chances that they'd notice the difference in traffic or whatever and shut off my port?

From the point of view of your apartment's router, your router is just another device connecting to the network. Since you control your personal router, you can then connect as many devices as you like (and your router supports).

Your router will do all the network address translation on your local area network, so it will make no difference to your landlord how many devices you connect to your router.

As far as wi-fi is concerned, modern wi-fi routers can automatically select an unused channel within the frequency band, and there are are two frequency bands available (2.4GHz and 5GHz). It should not cause interference to anyone else, and I find this claim fairly spurious.

Wi-fi is designed to work even when many stations are in close proximity. Most city apartment blocks or even office blocks will have many wi-fi stations in the same area, all working together happily. Just be sure you leave the channel selection on auto.

If you're concerned about being caught, you may like to disable the SSID broadcast on your router once you've connected your device(s), and perhaps turn the router off when you're not using it. Alternatively, just turn off the wi-fi functionality (or get a router without any wi-fi) and use only the ethernet feature.

I've posted some additional thoughts about security in situations with landlord provided internet in this answer.

Let me know if you have any follow-up questions and if I can answer them I'll update my answer or add comments below.