When you plant seeds of cultivars of Apricots  (tomatoes, peppers, plums etc) you will often have similar plants to the parent however they may also be very different depending on how the genes from the pollen and egg combined whether they were self pollinated or cross pollinated.  So when your seedlings grow bloom and bear fruit in 7-10 years the fruit may not look or taste the same as the Angelcot fruit from which the seed came.  Nonetheless Prunus armeniaca are hardy in our area.  Apricots don't need a lot of fertilizer and you would do that during spring/summer if needed.  Below is a good calendar/information publication from California where most Apricots are grown in this country.  Some of the dates would need to be shifted since they are milder than we are but still a good basic reference.  Pruning would be best following the 2nd Virgina Publication looking at the Peach for Apricot pruning in June/July
http://ucce.ucdavis.edu/files/datastore/391-603.pdf

http://pubs.ext.vt.edu/430/430-460/430-460_pdf.pdf

http://pubs.ext.vt.edu/422/422-025/422-025_pdf.pdf

You can call the Virginia Beach Extension office at 385-4769 to speak with one of the Master Gardener Volunteers regarding fertilization when the trees grow larger and/or if you have other Horticulture Questions.  They are also in Building 14 at the VB Municipal Complex

Should we keep the pots outside this fall and winter, or should we keep them indoors?

You should leave them outside so they can go through dormancy.  You can mulch the pots with leaves but they should be perfectly winterhardy.  Mice like to gnaw on young fruit trees so you may choose your location appropriately and check on them from time to time in the winter.