IJN DB: I think after unlocking the Type 99 at lvl 75 i suggest that there should be a 3rd upgrade at lvl 100+ and it should be the DB  D4Y Judy which was an updated version and more modern version of the Type99 DB
IJN TB: The current TBs are perfect. No changes needed!!( GOODJOB!!)
IJN FP: I recommend adding the raiden but it should be a high lvl FP like around lvl 115+ and should have a higher speed and attack then the shiden.
IJN Kamekazi: This would make the IJN CV line interesting. Maybe consider adding a bomb packed zero and an Okha flying bomb as an upgraded