@Kamilla8
1) Everyone's a little different there, but personally I hate finding decorative pillows on a bed. It just seems ridiculous to make a bed with items that someone isn't supposed to sleep on, while leaving the items that are actually useful in the closet. You might think it's nice presentation, but your guests are stuck with the tedious task of putting those pointless pillows somewhere off the bed where they don't get dirty while still finding enough room for their stuff.
Imagine you're at a restaurant, and your table is covered with candles and flowers, and then when the main course arrives, there's no room for your plate, so you have to stick a bunch of vases on the floor, and then your meal is hiding under a few beautiful green leaves that may or may not be salad. Does that sound weird? Yeah, well to some people, so are your shams.
2) There's no right or wrong frequency for bathing. But what most guests can agree on is that it's "not normal" for a host to be monitoring their bathing habits when they rent an Entire Home property. Some might even find it creepy.
3) They're probably not trying to save you work; they're just doing what feels comfortable to them. The more variables you make possible with all the different layers and types of bedding, the more variations people will come up with to customize it to their own comfort. Everything that goes on the bed has to get washed at changeover anyway, so I'm personally inclined to keep it simple.