My 2 1/2 yr old is able to get into the bathroom now (altough he still need help when he uses the potty). Most of the stuff they can get hurt by is way up high or in locked areas. We store extra soap, shampoo and stuff like that on top of the stackable washer and dryer & there is no way of climbing them. One thing my kids do like doing is getting a cup, filling it with water and playing with the water (getting it everywhere). We took out all the carpet in our house (execpt at the top of the steps - slipping factor) and put in laminate floors (all 4 bedrooms, livingroom & dinning room) and tile (kitchen, bathroom & foyer) - that way they are easier to clean up messes & less issues with our kids allergies.
As for climbing - my 4 yr old love to do that... he has even climbed up on the kitchen conter then on to the store to get to the candy. Just remember - if they really want it, they will find a way to get it.