Context:

Most of my life I have lived with flatmates or partner or family members and we will shoulder responsibilities in managing things. Now I am living alone in a one bedroom  apartment in a new continent(EU). I am loving it and doing much better than expected managing things. BTW getting a used Roomba on a whim was  a game changer. I am not lazy but have ADHD and just forget things or am not able to sequence things. But that's a long story. It's a rental apartment in from maybe 1980s. So it has a lot old equipments(traditional apartment lock with long-ass key), gas burner stove etc. I have the following requirement, please suggest me setups considering it is a rental- hence they can't be intrusive, I should be able to remove them when I leave the apartment, they should have low touchpoint.
While suggesting: you will do my brain a great favour if you give specific details(which hub, which networking type, specific sensor model etc). I know I should be making my own choices but my ADHD brain makes it a PhD thesis in comparing trivial alternatives. Also- cost is a factor. This is not some permanent dream home situation so hopefully in between 200-300€ max. I lose interest in things and then leave it frozen wasting money. Simple solution with predictable linear steps with little maintenance would be very helpful.

P1: Proven life improvement

1. Apartment door unlock from phone: Without replacing the apartment lock, is there a way to unlock the apartment door. It's an old school lock with a big, long obnoxious key which you twist to open. I have an anxiety of living the house without Key. I have done this so many times in my 20s. Now I don't but as I have anxiety to check the keys in my bag/pocket frantically before I leave.
2. Main door unlock from phone: Main door of the building has a buzz-in system (+ camera if it matters).  I read somewhere that one can use a button pusher, not sure what it is and is the best solution
3. Automation: Buzz-in a particular Food guy daily between certain times- A guy gets me home-cooked food delivered everyday, he comes between 12PM-2PM 90% of the time. All I need to buzz him in and he can leave the food on the apartment door knob. We can automate this by either on-receive of his whatsapp call or maybe something smarter(give some NFC thingy but wouldn't it require changes in the building door which I can't. Another solution could be he showing a QR-code to the camera and then... But I am sure there must be more robust/elegant solution to it.
4. Buzz-in someone from phone: I think #2 will solve #4 too?
5. Gas burner auto time-out: I have old school gas burner stove with old-school knobs to turn on/off. And my fancy-pants brains sometimes(very rarely) forgets to the switch off the gas and flame keeps on burning.
6. Gas stove knob control: I make tea almost 3 times a day- I boil the milk and tea grain on high flame and then after 2-3 minutes I need to turn the flame to (almost)lowest. Every other day milk spills over as I either forgot or was late to lower the flame. I spend decent amount of effort in a  week to clean up the stove area. (A good to have will be timer based switch-off which is basically turning the knob to max. There's no way to automate switch-on as it needs a flame from a lighter or a clicker to be held near the mouth to switch ON. I wonder if we can do something about it too.)
7. Bedroom light automation: I have trouble sleeping, so I switch off everything. It gets pitch dark, I bumped my head (almost seriously) walking in the dark. I plan to buy an LED strip with ESP32 or something and put under/in the bed groove very dimly. When I switch off all the lights in the bedroom and pull down the blinds(it uses a belt), it switch ON the accent LED lights if person/motion is detected not sleeping or something. And whenever I wake up to pee auto switch-on the leds etc. Right now I use Phone torch to come to bed once pitch dark.
8. Monitor back LEDs: I work remotely, have a 43" monitor. Need LED behind the monitor which change based on the light from the large windows near it(less light, brighter LEDs). Should I go with DUMB LEDs for the basic use-case? AMBITIOUS: It will be super if they can switch ON when I am on a office call(integration with google calendar? Or me speaking?) as I only need them for the camera. It will be great if they can auto switch ON with low brightness say between 8PM-12AM and later in the night they will always be ON if they detect human movement(not getting falsely triggered by billowing of the nearby cotton curtains. Yeah it's windy here)
9. Bidet: This is more of a traditional ask- what's the most non-intruisive way to install a bidet in a rental apartment :D ?

P2: Good to haves

1. Switch off bath tub taps if the tub is almost full: I love to put a bunch of things and bathe in the tub once 2 weeks. It takes forever to fill up and I have to keep on going to the bathroom to take a peek, if the tub is almost full. It has old school taps- one hot another cold, independent of each other. Hot water is coming from a central gas heater in the kitchen.
2. Make old school hot and cold taps remember the ratio: I look like a foolish scientist calibrating the hot/cold taps to perfect temperature every day for bathing. And in between when I am lathering myself to switch off the water I have to turn both the taps again to zero. And when I need to resume I am again back to being a foolish scientist. Is there a clever way(analog or tech) to solve this.
3. Commonly used Inventory tracking: Milk, Kitchen roll etc
4. I will get a simple box fan or a portable AC(since it's a rental)- is there an easy way to control/automate basic-fans, ACs?

P3: Ambitious

1. Bedroom blind up and down + automation: I have these old school blinds where you pull the thick belt on the side to pull them up, and loosen one side while gradually letting loose of the other side to let them down. It's an old setup so it cranky, heavy and janky. This is a very important requirement but have put P3 as the setup could be messy and not worth the ROI

2. Buzz-in control on chrome/desktop: Most of the time I am sitting on my chair working on my office computer(heavy security and restrictions) so it will be nice if I can buzz people in from the chrome extension or something. I can map a key on my logitech keyboard to trigger the buzz-in too.

3. Pet manager/feeder: I never had a dog, never thought of having one. But over the years very slowly I have been getting attached to them. I live alone so that nudges me and also scares me to have one. But  I am very scared of my forgetfulness and being the single point of failure for them.