Security will be taken into the 21st century. Rather than physical keys, a bluetooth/NFC/RFID device will be used. Every tenant will be given a key card to access their approved location. I will have full control access to all units since I am the owner. In addition, rather than me having a key card, I will have an RFID chip inserted into my hand. This is about the size of a grain of rice, and intended to assure that I will never lose my key.
There will be security cameras everywhere. This will keep people on good behavior when in the building. This will also catch thieves, or bad actors. The cameras will route to a surveillance server which will be located in the communications room. This will keep all footage locally, and therefore not have to pay for storing on the internet. The cameras will allow me using the HAI panel to see who is at the doors, and respond appropriately. Since this building is not a house, it will not make much sense to use a Ring Doorbell camera.
There will be cameras in the apartments, but only in the common spaces, and not bathrooms, nor bedrooms. If someone breaks into the apartment, there is a chance that police will get footage that would help identify the bad actor. All of the cameras are tied to the appropriate network. The second floor apartment will have cameras on the 192.168.2.xxx network, and therefore 192.168.3.xxx can not view these cameras. This will help set up privacy, and there will be a surveillance server that would store the camera footage for 90 days.
Each unit will be responsible if they should wish to have an alarm system installed. I would truly doubt that using various sensors from just any company will work with the proposed security company. However, my personal residence, and the business(es) in the building will have an alarm system which I will likely use SimpliSafe.