My 2 boys were only 20months difference but DS1 still had a lot of toys with smaller parts- particularly his cars (i know they are meant for 3years and up but DS1 has loves his cars and has never been one put things in his mouth). We just kept all smaller things up (we still had/have things we supervise them with) and other stuff in DS1s room. DS2 has also not been one to put things in his mouth (probably helps he usually has a dummy to plug it...lol). I can't recall ever having a problem and my 2 are just over 3years and almost 18months old now.

With the toilet and bathroom- which was one of my main concerns as i figured DS1 would be toilet training when DS2 went on the move- and thats all turned out ok- we keep the doors closed and DS1 can easily open them when need be and knows to close them because of DS2. I guess thats probably been the main thing is to teach DS1 to keep everything up or away otherwise DS2 will touch it- which will means it'll get broken or it'll be 'ouchy' for DS2- DS1 seems have always understood this.

Goodluck.