#1 - I think you want to use the combobox's "After Update" event. Then grab your recordset and assign the form fields. (I'm speaking generically, because I usually use SQL pass-through which makes the data-access portion a little more difficult).
#2 - You can use code to write the address info to the address table, but it might be easier to just use a subform so you can save info by just using a "Refresh" action.