There is a portrait painter in my town who does fairs and she sells pictures she has done of current movie stars all the time. Can you do that?
I'm afraid this kind of thing is done very often - the original photo is copyright and strictly speaking the artist should first seek permission - they seldom do. I think the attitude is taken that the images are almost public domain stuff!
So it would be up to you!
As for your painting, if the photographer gave you permission to use the photos, then you can do what you wish with your own painting.
Any income from sales is yours.
It may be nice (and appreciated) if you were to credit the photographer and individuals for graciously giving you permission - again, that's not always done!
If the two other dancers haven't replied, well, you had permission from the owner of the image made, so it should be OK - or you could change their faces!
Copyright law is different in each country - it might be worth your while just to check it out.