The EB script spawns only government buildings. (Since the AI doesn't know how to handle them or know that they are needed.) All other buildings have to be built normally and I'm pretty sure at normal speed.

The population replenishment script adds 200 (on Huge settings) people every time a infantry unit is recruited. If the town is recruiting elites with 160 men per unit they are actually gaining population. If they are recruiting levies with 240 people per unit they are loosing 40 for every unit the recruit. If the town has very low growth and is recruiting a unit of Pantodapoi every turn they may actually end up depleting the population.