Look around at allies with similar cost and see if the stats are the best you can find. Formulas dont work and are best avoided. Check activity as well, as this also contributes to pricing.
Yes but towers go better with certain builds. A tank build, which I am in the process of building, depends on towers to survive. Shadow hansels require no towers, as do pure spies. A proper war veteran could help determine what sort of build you should go for to war.
when you get all lowlands, is it better to max out all buildings there or go onto the highlands and keep building? not quite sure what to do, and i want to mass convert after getting all lowlands.