I don't know if the female is laying eggs but I haven't seen any fry. There are plenty of places for fry to hide if they did make it past egg stage.
There are 3 that are fat slug shape loaches and 2 that are long eel shaped so I think 3 females and 2 males. Not sure why Mr Skinny is skinny - as I said before his personality is more alert than the others a lot of the time and I suspect he is a male and more nervous than the others. There is another one that is thinner than the fat ones too, but not as skinny as Mr S. I read on the loach forum that it can be caused by worms but I haven't seen any signs of that other than weight, and I haven't dosed the tank. I have seen him graze over the food without eating it, and at other times hungry and chasing it so I think it is a social issue rather than a health one, but who knows. I am just guessing really. I would be sad to lose Mr Skinny as he has a lot of personality, I should probably get some wormer and give it a go.