When to sterilize, and when to just give it up

When I was first shopping for all the baby stuff we could possibly ever need, one thing I came around was this microwaveable sterilizer. We bought the advent one, not to plug a product, but its been pretty cool. And what we do is after everytime we hand cleaned bottles, nipples, soothers, pumping stuff, we would then throw it in the sanitizer, two minutes later, boom its clean, then we throw it on the drying rack until we need it, or until its dry then put it away (normally the first... especially when your tired).

But I then started taking the lazy approach, I started to use the dishwasher. And whats funny is I saw at toys r us, this plastic tray that seals up but has tons of holes in it, that you put all your baby parts stuff in, and throw that in the dishwasher so that they dont fly all over it. But our cuttlery area, has the same kinda compartment built into it. so I just used that, and for everything, except the bottles, those I would put on the top rack with the glasses.

Now keep in mind all of the above mentioned items for us are made of either plastic or silicone. And yes we use the BPA, Phosphate, and something else FREE items. Not too sure what that does, but they all say its good so we buy those. Anyways, after I put them through the dishwasher (keep in mind, I did realize it was the lazy way out, but I also thought it did a better job than I would ever do cleaning it). Then I would throw them in the sanitizer after it came out of the dishwasher, then on the drying rack.

Now Ive heard that we are WAY over using the sterilizer. That bottles, and nipples should be sterilized once, then just clean from that point on. Which makes sense dont get me wrong, I just didnt realized we do that so early. I figured after he gets his first few rounds of shots, thats when you say go ahead, go get dirty. So Im wondering what age did you stop sterilzing things? How often do you currently sterilize items? What do you sterilize? Any and all help is welcome!