If they wanted to fix the islands/bases taken by fire, simply make shells useless on them. As for retreating, you cannot stop that completely, but default map like no way out 1/2 helps.
Many people don't understand the amount of exp received if APA/Skytrains take all the islands and the main base. It is the best form of exp but rarely if ever happens.
Quite sad a promising game mode goes to waste.