Your whole flock should be culled it could a contagious disease if it is from the water if you dont want too you could try some antibiotics but its a long shot
Thay leg is broken a chick could easily recover from such a injury as they still have time to grow consult your local poultry vet they should be able to help with the leg
Thai game are most of the time larger than asil game , they have different origins and the asil should stand more upright and the thai should habe a low down facing tail
Not sure what type of gamefowl i have here i just got him today from a friend he is just over a year old and very aggressive looks like a game fowl to me not sure what he could be though
All help is appreciated