I love my dishwasher, and would not be without it.
You don't need to rinse plates as that defeats the object of having a dishwasher.
However, what you have to remember is that it is a dishwasher, not a garbage disposal, so you do need to scrape plates of any big food objects, or there would be problems.
I believe, you only actually need salt if you live in an extremely hard water area regardless of using all in one.
Luckily, I live in an extremely soft water area, one of the softest regions in England actually (reward for all the rain we have
).
I made the biggest mistake of my life in my last dishwasher, for some reason I decided to add salt, despite years of faultless performance beforehand. After doing that, all my cutlery came out rusty and non glazed pot (trims of bottoms of cups) had orange spots on them.
So I never made that mistake again, and don't need to use salt (suppose even I wouldn't if I weren't using an all in one).
I found THIS website interesting because I am sad :)