You do know that apartment complexes, those that do allow pets, require a pet fee? As far as the vents go, unless each apartment has their own system, like our apartment does, cat scent could travel to other apartments where Lon lives. But, if the Asst. Living allows pet/pets, they must know if anyone is allergic to any. If any are, then there should be a "no pets allowed" policy for the place.
Raises some interesting points. If an apartment complex allows pets, can someone who's allergic have problems if the guy 3 doors down has a cat? And you can't really base your policies on who the existing tenants are if tomorrow's applicant might have allergies. Honestly, I never thought of the allergy aspect when places banned pets. I always figured it to be a "pee on the carpet" concern. Gee, maybe they should have "No Peanut Butter" rental units.
Lon, I hope you can find a great little furry friend to keep you company. Please remember that pets are not maintenance-free and will require a lot of your time and attention, need vet visits, etc. Hopefully you won't have trouble with an "escapee" that dashes out when your door is opened. Do any of the other residents have cats? Also, you might check the local want-ads for pets. Many times private owners have kittens they need to find a good home for.
Which brings up another question. Male or female cat? Are you going to have it “fixed”? Just a small observation: It’s up in the air as to whether pets can get or transmit CV-19 so that might be another concern. Small but just the same, a concern.
It's not hard to train your cat to use the toilet------Forget about a dog. Cat using toilet and Flushes 1/2 - Bing video
From Zillow, in giving advice to landlords: Keep in mind that a deposit is refunded if there is no damage done by the pet, just like any other security deposit. Monthly rent is exactly what it says: rent. Ron's in Los Angeles. One would expect that to be on the high end of the scale. On the flip side, the risk to the property owner is rather low in Lon's situation, since their representative is in his unit on a regular basis as part of their duties.