The one big factor that you're ignoring is that of visas. Most countries these days require you to obtain a visa before you can settle in and live there. And it's the visa requirements that are most likely to trip you up in your quest for someplace to live.
Italy, for example, has rather high income requirements for "retirees" (and there is the question whether you can be considered a "retiree" with minor children in tow). Basically, any European country will expect you to have jobs lined up before you apply for a visa (not to mention the employer able to "sponsor" you).
You also need to consider the issue of language. It can be extremely isolating not to have the local language when living abroad. And there is also the issue of schools for the children - what are the public schools like and what are the requirements for enrolling the kids in the public schools.