It doesn't matter if they are in the same address or different. Each time your receive a tx its going to create a new unspent output.
So, you are still going to have the same choice of outputs for any transaction. I think spending money to combine your outputs is counter productive. Having all your receives into one address doesn't change the underlying protocol.
So there is really no dust consolidation? I thought there was a way.
You can spend back to yourself, but unless you use a wallet that lets you chose the outputs yourself, and set a very low fee and wait for it to confirm, it seems like much ado for nothing.
The wallet should pick the best outputs for any spend you do. having a bunch of smaller outputs makes it easier for it to find a more exact match to your spend.
At least, that's my understanding of it at this point. Dust consolidation at current tx fees is not worth it afaict.