I have a 10 year old, 5 year old, 4 year old and 1 year old. Only the one year old still naps in the daytime, only time the older ones will sleep in the day time is if they are sick or have had a particularly hard day at school (my 4 year old does part time school and she'll fall asleep after school on the day they have swimming) They (the middle 2) go to sleep between 8 and 9pm, we don't do a set bedtime- we never have done, we just work with them taking themselves to bed when they are tired and it works well for us. They're both up at 6am every morning, if not before, so it must be enough sleep for them. My eldest will usually take herself to bed at 9-9.30ish and reads until she falls asleep, she gets up 7am to get ready for school.
My 4 and 5 year old both help out around the house, they tidy their shared room with the help of their older sister. Everyone is expected to take their own plates out after a meal, everyone is expected to bring their own dirty laundry down stairs each day. Everyone is expected to make sure their water bottle and lunch bag is in the kitchen ready for the next day and school uniforms are folded when they change clothes. They can load or unload a washer, although folding clothes they have enthusiasm but not much skill

They help with pick up of the family room, my 5 year old likes to be the one to sort the recycling (he has special needs and one of his present obsessions is the environment so we support that) and the composting.
With cooking we like to teach them young- even the baby (16 months) will fetch and carry things in the kitchen- although someone has to give him the right thing or you'd end up with the entire contents of the cupboard he gets a bit over excited

. DD4 will fetch ingrediants and stir things, DD10 can cook a family meal if needed.
I think we've always had success in this by never making anything a chore- there's no punishment if it's not done other than the direct consequence (you don't bring laundry down you run out of clothes, you don't take plates out you're not eating next meal etc - it sounds harsh and weird but it works as it means i'm not the nagging mom, they're just reaping the benefits or suffering the downfall of their own actions) We just tell them everyone in this house pitches in because we're a larger family and if we all want to live in a nice house, we all have to help make it nice. Not having them see things in a negative light has worked well for us but we're quite an unconventional household.