We imagined it as a family seat for family celebrations, etc., where you can also hold larger events without it feeling "tight."
So, Big Manni is said to have been "satisfied" with 500 sqm (in Durlach, however, not within the catchment area of FRA, but close to Baden Airport). Everything you describe sounds to me like a "Lost Place 2040." By the way, I would N.E.V.E.R. get the idea to put my budget for holiday properties into ONE property in GERMANY. And by the way, not to add another 600 sqm just for tax savings to the 200 sqm that are then sufficient for generous living for two adults and two kids from the family house (an effectiveness of which I doubt, by the way), where you then already need a traffic control center for the vacuum robots. Why actually Wetteraukreis? - Vilbel is quite nice, but from Ffm I would rather get to Hofheim, Glashütten or Idstein.