In the starting ages you must protect what's important, gold & food, simply so you can progress in the game. If you can manage to do that you can get to IA sooner, thus unlocking the best of what the game has to offer. Come IA, whether you mean for it to or not, the game becomes more so about medals than anything else. Especially once you pass a certain threshold of medals. Players don't go for the loot, they go for the kill. Hence my layouts now focus more so on protecting the CC/FC (attackers gotta take out both to get the star). You shall soon realize this
Regarding #2, kinda depends on your playstyle to be honest. I like having a second town center, & protecting as well. Players gotta send in the whole battalion to try & take it out. Which gets me free crowns. Who can argue with that?