How great is this, its making me reminise.
I grew up with 3 sisters oldest are twins, then another sister, then me. My parents were strict with sum things and fun with others, but I like their parenting style and Im gonna parent the same way.

Jumping on beds-No but we do wrestle.
Swinging on the clothes line-Absolutely, we did it , 1 girl on each corner, the 'hills hoist' was totally balanced so it never got lopsided, dad would spin us really fast.
Blowing bubbles in the milk-Isnt that what milk is for?
Water fights inside-No, outside is fine though, watermelon seed fights in summer are good fun, see who can spit the furtherest. We used to throw buckets of ice water on each other in the shower also.
Balls inside-Depends where,if its safe. We had a long hall growing up and we used to play dodgeball, marbles and sometimes 'baby' cricket down it.
Manners are a big YES. Xander doesnt get anything without a please or thankyou.
Days off school are a big NO. Nick was a terrible 'wagger', and I dont want my boys to have any leeway with days off incase they turn out like him.LOL