Kale and parsley together isn’t really recommended to be fed every day. Parsley is high in oxalic acid and kale is high in calcium.
Oxalic acid binds with calcium and magnesium inside the body to create oxalates. These oxalates then need to be expelled by the body in the urine. It also means you cannot absorb the calcium and magnesium that gets taken away to create the oxalates. In humans, one side effect of too many crystals building up is kidney stones. Oxalic acid in large quantities is also a poison, which can cause kidney problems as well as joint issues. In humans, you’d have to eat A TON of it to really hurt you, but bunnies are much smaller and process things much differently than we do.
That isn’t to say to AVOID foods that have it, by no means try to do that. Many foods have it and as long as it’s kept in moderation, it’s perfectly safe. Their bodies naturally expel a pretty good amount of it every day with no issue. Just try to keep the parsley on a rotation of every couple of days, instead of every day.
If you fed them carrots and basil and they never had either before, it’s possible it caused a slight digestive problem which caused a few mushy pellets. I wouldn’t worry unless you notice other symptoms. New veggies should be introduced one at a time and slowly (small amount one day of one, then if it doesn’t do anything you can give them a little more just to be sure, etc).
The noises when they drink is normal. Have a person drink some water and listen to their stomach area as they do so. There are noises too. 