Your landlord sounds like a typical clueless accidental landlord. He is doing his best and repairing little things for you but doesn’t have the cash flow to fix a window. He is apparently so ignorant he hadn’t protected your deposit, did not give you how to rent booklet (easily solved by emailing you a link), had not ever done EPC, does not ever test the gas appliance, does not install carbon monoxide alarm (do you have open fire or gas appliance) does not have fire and smoke alarm, does not have electric safety certificate. What does he do other than taking the rent? This isn’t the Victorian period, is he aware of that?
He may have all the best intentions but housing other people and children is a serious matter and landlords like him that give landlord a bad name. All the above regulations are readily available on so many websites. Any 30 seconds research will give him all he needs to know.
No need to think about eviction at this point. There is a huge backlog of eviction notice countrywide due to eviction ban, and he cannot possibly benefit from eviction notice when he hasnt adhered to any of the regulations.
Fire, gas safety and electricity certificates is what i am more concerned about. As consequences could be deadly if anything goes wrong. and they don’t cost very much to put right. Provided the property is safe and up to standard, getting the certificate and alarms shouldn’t be more than three/four hundred pounds.
If the testing flags up any issues they should be solved immediately as you have two toddlers and he has a duty of care.
Window should be fixed so that it is functional. Asking for a upgrade could come across a bit cheeky and he is unlikely to agree. Money should be spent on testing and making the property safe. The green grant is however an excellent suggestion, ideal for accidental landlords.
In the future, avoid landlords like him. Cluelessness will land both of you in trouble. To move on you need to pass credit check some agents ask for landlord reference. It is best to work with your clueless landlord than reporting him, unless benefit and council housing is your goal of course.