I have been finding and researching a lot of teeth from Kimmeridge Clay lately, so interesting to see yours...probably Cretaceous, not Kimm.
(1) Croc..................possibly Steneosaurus/ Teleosaurus (Teleosaurids). I think Dakosaurus and Metriorhynchus (Metriorhynchid type of croc, with blunter, wider jaws) have teeth with slightly serrated edge. But I have only gleaned this from the internet pics from search eg Metriorhynchus teeth). I have got several Steneosaur teeth , approx same size and shape as ur no.(1). Steneosaurus has a line down each side, extending only half way down from the tip.
For Kimm clay info google â â â â â â â Ian West kimmeridge clay fossils
This is mainly about dorset but has plenty of info on crocs, plesios, plios found, plus links to other information on line. I have also been using "Fossils of the Oxford Clay" Palaeontological Ass., edited by Martill and Hudson. The chapters on fish and marine reptiles give a good basic background and some genera go on into the Kimm, etc. There are pictures of teeth, fish, croc , Ichthy, plesio and plio. Plio teeth have much deeper ridges and as u say the amount they go up the crown towards the tip is diagnostic.
(2) I agree with others , looks like the central cusp of a Hybodus shark.â
(3) Button like teeth look like Pycnodont fish teeth, broken away from the palate. Leptidotes has round button teeth like this, but so do other species and I'm not able to id yours. I personally have not heard of croc teeth like this. I thought the back, crushing teeth of crocs were much stouter than this, more robust, and wouldn't they have some sort of root as reptiles, whilst fish teeth look like your specimens.
Any way hope this helps, cos its a fascinating topic. I hope to post some more tooth photos(KIMM) soon. Look forward to any ideas you have. I shall be going to my local museum to help with ids too.