Hello eherb.
I think your considering moving to Andorra is a great choice.聽 I did it almost a year ago, and i have nothing but good feelings about it, no regrets at all.聽
It is a great little country, at least that is what i think.
About the languages, i would not worry so much, most people speak more than two and a considerable number of people (minority)speak English too. You do not need to know Spanish or French or Portuguese which are normally used by many.聽 All you need to know is Catalan which is the only official language of the country and virtually spoken and understood by everybody in Andorra.聽 There are ample ways to learn it for free.
In regard to your children schooling, i recommend you to refer to the following link, mainly on the section "Guia In-Format":聽
It is in Catalan of course, but you can get a fairly decent translation into English using the the following free on line translator:
Take care and good luck. If you need more info let me know.
Txabi
