PK x CT possibilities:
Basically I agree with Basement betta - you will not get any good form of either. The CT will have uneven web reduction while the not CT may show some spikes. You will also get short, long and in between length of fins.
Crossing CT to anything should have specific goals - eg. To create a dragon version CT, to create short finned CT, to improve CT fin spread .... etc. Without goals, cross breeding is meaningless and will only produce what people often call "mutts"
Dragon X non dragon/metallic =
regular and partial dragon. You have to keep inbreeding the partial dragon to eventually return them to dragon scales.
You will get a variety of colors - cambodian like colors, black/blue - red fins .... to name the least.
Dead fry will usually look sort of milky as it decays and sort of swelled. Fry not moving (at all) at the bottom is probably first signs of problem. Normally fry should move once in a while searching/scrounging for food. Do more water changes, frequent small amounts in this case is better than one big water change as it will not shock fry. Drip system refill is also a must.
It is safer to take male out once fry freeswim - meaning fry are in a horizontal position and swim like normal adult fish. They're no longer swimming in a sporadic circular motion. But known good fathers can be left with fry until they're big. My longest is about 2 months (respawn father) but I know breeders that can keep them together until 4 months.
2 week interval between spawns is safest, giving male time to be reconditioned. Sometimes males won't eat for a few days after they're separated from fry. So they need a longer time to get reconditioned compared to females. BUT males will immidiately respawn if given a female once separated from fry (not advised).