Hello and welcome to the forum. I'm not 100% sure but withouth having them 'in the hand' it's the best I can do!
- I think this is a mixture of bits including Pyrite.
- This looks to me like a typical phosphatic nodule possibly with crab bits.
- A very worn part of a Septarian nodule
Thank you so much for your reply! It's been very helpful, sometimes simply having the right terms to Google and explore to compare finds too is so helpful, so thank you!