This sounds like a few different issues.
Combining Loads on a Circuit
There are certain circuits that are required, by modern code, to be dedicated. They include:
- Bathroom Receptacles - Can be shared by multiple bathrooms, can be shared with bathroom light/fan. Can't be shared with anything else.
- Kitchen Receptacles - Two separate circuits required. Can be shared with certain related rooms, but not with bedroom, living room, etc.
- Laundry - One dedicated circuit required, normally used for washing machine.
Most other things - lights, bedroom receptacles, living room receptacles, etc. can be combined. So it sounds like you have a violation with respect to the bathroom receptacle circuit.
Bathrooms are required to have an exhaust fan or an operable window (minimum dimensions apply). There is a relatively new requirement in at least some places for the fan to run automatically based on occupancy or humidity or other factors. I think running a fan 24/7 would be a waste of energy but not in and of itself violate any rules. However, if you have a speed adjustment, it will typically also include "off", unless it is totally automatic. An automatic humidity sensor that fails "on" could cause the fan to run all the time with no obvious way to turn it off.
I recommend talking to the landlord/management company. You can't make any changes to the circuits yourself (because you rent). They likely won't want to spend the money it would take to bring the circuits up to code (that could easily take several hours of an electrician's time), and if pushed on that you may find they come up with an excuse to not renew your lease. (Not good, but it happens.) However, they should be interested in saving money. If a fan uses 50W x 8,395 hours/year (i.e., assuming you actually want to use the fan 1 hour/day) at 0.15/kWh, that is costing them $ 63 per year. Not a huge amount, but worth getting an electrician to fix it.