Ianc1

I Don't use nmm but the file update.esm is a hidden master file, I think is comes from 1.4 patch upwards, so as long as you are running patch 1.9 there should be nothing to worry about.

The children's room is available from the steward once you install hearthfire dlc. The letter to adopt kids only comes when grelod the kind in riften orpange is dead. There is a bug where if you adopt a child without a childs room available you will not be able to aport. There is not lvl needed to get the child's room if it is not showing up then check you have installed and ticked the box for hearthfire.

Your running the wrong version of windows, you need to run 64bit to make use of the 8gb of ram, 32bit only sees the first 4gb. Have you checked the ram by pressing F8 during boot up and going to check ram option.