I wouldn't get any more than that to start. Some babies don't like to be swaddled and I only washed them when they got dirty. And no, no other bedding is needed. Though lap pads come in handy to put under their head or butt so you aren't constantly changing sheets or changing pads.
We have 3 miracle blankets and I think that's perfect. I have 3 of most baby items. One that's being used, one that's in the hamper/washer/dryer, and one that's clean. That way, when the one in use gets dirty, I have a clean one ready to go, and a new clean one on the way. I think what you have sounds good. You'll never know which swaddle she will like. DS sleeps really well swaddled, but he busted out of everything but the Miracle Blanket. So we have 3 of those.
As far as crib bedding, we have two mattress protectors, and 3 sheets. Buy two mattress covers/protectors. You want to be able to put on a clean one in the middle of the night.
Also - do I need any crib bedding beyond the blankets and crib sheets? I have a mattress cover already.
Lesson learned- you need 2 mattress covers. We've had several middle of the night sheet/mattress cover changes and had to go back to the store to get another after the first change.
DS did not like to swaddle so the one sack I had was worthless.
I loved the A&A blankets and didn't need much else. We were gifted several blankets as well. I also like the sheet savers for the crib- I'd put them under DD's head in her crib when she was sick so that there weren't boogers all over her sheets. I also really like the breathable bumper.
we aren't using the A&A for swaddling right now because G is so small and the blankets are so big! We are using the swaddleme/kiddopotamus swaddle sacks with velcro. She is still too small for the miracle blanket.
we have 4 of the sleep sacks, use each one for 2 days, then wash, unless they get dirty. They kinda get stretched out after 2 days. I have 2 miracle blankets for once she's bigger.