1. YES. I bought a couple rolls of bamboo liners but the breastfed poop was just too watery for them to be of any use. So I stopped using them and got them out again soon after bub started solids.
2. YES! But that's because I wanted to change our boy as soon as he wet himself. We didn't use covers, just had the flat nappy. That was when he was a bit older. We used prefolds when he was fresh out of the oven so-to-speak.
One exception... DO use a cover when bub is sitting on mother-in-law's lap and hasn't pooped all day.