Good job with the maps: they look nice.
I think the seemingly reduced intervention of the Valar after the First Age was not necessarily due to the Sundering, but rather with the realisation that their earlier acts may have done more harm to the Children than good. If they had let the Quendi be and not summoned them to Valinor, many of the more tragic events of the First Age would likely not have occurred. The reaction of Mandos to the decison to make the Summons is like a death knell:
Perhaps he was thinking along similar lines.
In the Second Age the Valar had much less to do with the Edain in Númenor directly, seeming to be content with keeping a watch over them. The mistake there was giving mortals a place where they could physically see a land with no sickness or death.
That the Valar would take the trouble to clothe Maia in physical bodies and send them to ME in the Third Age, taking pains that their representatives be as discreet and humble as possible tells me simply that they had learned from what they perceived as past mistakes.
x'd with
Morthoron