I wonder why the young boy on the upper right part of the triptych is not depicted as a saint
I need more time to look more closely at the icon as far as the other saints are concerned, but regarding the saint on the upper left-hand side holding the child, this could be St Stylianos of Paphlagonia, who is regarded as a patron of children, and is shown in his icons holding a child or baby in swaddling-clothes. St Stylianos was a monk and hermit, and this fits the appearance of the saint in your icon.
Two people on bottom right corner can be St. Apostles Peter and Paul.
Probably not, as Apostle Paul is always shown with dark or black hair and beard.
I'll post more once I've had the chance to look at the icon more closely. Is there any chance you could photograph each section of the icon (preferably in daylight, as this will be clearer, because using the camera flash puts a glare on the photo) and post the pictures here? That might make it easier to work things out.
There is also a good chance that this icon was originally pained as a "family" icon, where the saints are the patron-saints of individual family members.