It seems like they are sold in bunches of four, I don't want to over buy.
Will depend alot on how small the baby beets are. If they are bite size 0 which they can be sometimes, I'd get more. Otherwise 2 dozen should work
2 dozen for that many people is less than one beet per person. Assuming they're small ('baby'), I'd double it. At least.
Yes, they are bite sized, rather small. I don't want them to overwhelm the salad. I think I might go with 3 dozen
You might want to just give the full menu