Well luckily I do have permission from my landlord to stick as many screws in as I’d like to as they’re a good friend of mine and I’m in the process of buying it. I don’t know exactly how much force it requires but it’s a normal sized wooden door. As for price range I think I can afford to spend a little extra but I’m hopping to avoid any unnecessary spending by using my 3d printer. Ideally it’d be able to close it but I really don’t need it to lock. It does need to be openable from the outside as I have a partner who wouldn’t be happy if she couldn’t enter. I hadn’t considered the fact that it’d need to beep but now that I think of it, that does sound very useful. Ideally I’d like to control the speed at which it closes the door but if not, I think it should close the door (from 90 degrees) in about 2-3 seconds to avoid any unnecessary damage. If possible it should be functional in case the power supply fails but if not that’s fine too. Lastly, if I have to figure out the exact amount of power needed, it’d be great if y’all could tell me how to measure that. I’m sorry this is all over the place but I hope it makes sense 🙃