For much of this you will require the cloud and a community create app called ADT Tools 2 to do. The ADT Alarm doesnt send commands natively to Smartthings so ADT Tools will help by performijg some of the tasks for you when the alarm is triggered. This is also a good time to look at what other smartapps are listed and install them. For some reason Smartthings removes many apps after the ADT hub is added so if there is a smartapp that looks like you will use it add it just in case.
First when you get the panel but before you add it to the Smartthings app lets setup your location. Load the Smartthings classic app and with no sensors simply install Smart Home Monitor. This will simply enable some features in ADT Tools that will not qork otherwise. You could also install ADT Tools at this point as well if you have all the needed IDE stuff done.
Now add your ADT Smarthings panel and start adding your devices. If these devices are already connected to you iris hub you may nees to do reseta or zwave exclusions to accomplish the adds. Start feom things that are close to the hub and work your way out so you can hopefullu get the best mesh network for zwave. When adding the dual branded sensora make sure you go through the ADT security setup and assign them the appropriate naming and sensor type so the ADT Alarm know how to properly use the sensor. Do you walk tbrough test to make sure each sensor is working properly.
At any point you can add the cloud pieces like the ring cameras and doorbell.
Once all your devices are configured there are a few smart apps you will likely want to use. You will want to install the smart lighting app. It is great for automating most functions with lights and will be 100% local if the bulbs and switches it uses are local.
Now requirement 1 can be satisfied with either using all ADT sensors that monitor those kind of events or using some notification smart apps like “notify me when”. ADT tools also enables enhanced notifications as well with any sensor.
Req 2 can be done with ADT Tools 2. Indont know of any other all in one app that does it. You will just need to setup the correct alert action in ADT Tools.
Req 3 can be accomplished in part by Smart Lighting. The simulated presense is a bit more complicated, but i do believe there are community driven apps that will turn on and off lights for this purpose. Room manager is one that comes to mind bit not sire how well it works for it.
Req 4 is simpley adding the alexa skills to integrate with Smartthings. This should be easy
Req 5 may be difficult since the ADT keychain functions really outside of the smartthings side. The keychain would work, but likely without a schedule. I would suggest just giving her a code on the Smartthings panel that has a schedule associated with it.
Req 6 will be a little hard as i think most cap at 15 amps. I have heard it has been done, so i know something is out ther.
Your nice to have can be accomplished in one of two ways. Either a app from Rboy or lock manager. If you look at the ADT Tools 2 wiki at thingsthataresmart.com it has a lockmanager fork that was updated to work with ADT Tools and the ADT Smartthings panel.