Yes, they look to be some type of mix and yes, you have at least 2 cockerels in there, maybe more. Well they are pretty!
I hope others can give better advice, but I have introduced my pullets/cockerels as early as 3 weeks old and usually have fully integrated by 6-7 weeks old by keeping them in...
It sounds to me that you are doing all the right things by introducing them with the "see no touch" introduction for a few weeks. Do you have multiple water and food stations? If not, you might try that so the newbies have options for food and don't get bullied from just one area. Just make sure...