The mix of sowing medium is probably fine, what you've done incorporating the Jiffy mix into the Miracle Grow is lighten up your end product with more peat and vermiculite. All of the nutrients for germination and early growth are already contained in the acorn, you don't need to concern yourself with that right now. Thoroughly wetting the sowing medium initially is good. From there, rather than on a schedule, you'll want to insure it's continuously damp, neither wet nor allowed to dry. It sounds like you may have your acorns a little shallow - "Stratification: Cold stratify for 30 days or until radicle emergence. (this has been done for you by mother nature and you are seeing the radicle/root in the acorns you collected) Germination: Sow seed 1 to 2 inches deep, tamp soil, keep moist, mulch seed bed." (suggestion for sowing outdoors) There is the chance if rain has fallen since the tree incident the chemical was moved through the soil to the area from which you collected the acorns, but don't despair - it seems propagation of these trees has been in effect for quite some time. Not to say you should not be attempting to grow your own, but "Auburn University's School of Forestry and Wildlife Sciences has been growing -- and selling -- baby Toomer's Corner oak trees grown from acorns from the same historic trees"...From what I'm reading they have some at different ages now - it will be years before the original trees can be replaced with the now seedlings but there steps are being taken to decontaminate the soil, reinstate them.

'... I think that these trees @ Nat'l Arboretum and the one @ UDEL, Newark are the northernmost Live Oak in eastern N. America....' Well, Newark Delaware is pretty far north, but certainly there are live oaks growing further north than the Nat'l Arboretum. I know of several in Sterling, VA, for example. That's quite a ways west too. Lots of acorns in my trees this year. Quickly becoming squirrel food. I don't mind. At least they're not bothering persimmons this year. And what am I going to do with hundreds of acorns?

Having lived in coastal SC for many years, and being familiar with young Live Oaks, I can tell you that they vary HUGELY when young. Everything about them is a challenge to ID. Notched leaves and all. I've seen so many that I could have sworn were young Yaupons, that I'm embarrassed to confess it! I think you have to trust your nursery, though I'm perplexed as to why you purchased your trees in another state. Do you still have them staked and wired, or am I seeing things? If so, you need to get rid of all of that.

Hot climate species not successful in Britain.