Can kits, such as Alpha or Flite Streak, be used if they contain solid (balsa or foam) surfaces, if they fit all dimensional rules?

Yes. Para 3, construction parameters does not define the structure or construction methods, it only limits pre-glued joints on kits and no boron fibers. Thus a solid sheet foam or balsa wing is acceptable assuming all other parameters are met. Additionally, we are not saying any particular kit is OK, only that solid surface aerodynamic surfaces (wing or tail) are fine. Rest of rules would also have to be evaluated against particular kits at the time of the tournament.