Continue to feed as long as they will take it especially if you installed them on new foundation. The inside feeder is a better choice in that the outside feeders are more prone to robbing and more likely to get moldy especially when exposed to the sun. Keep the entrance reducer (you should be using one) small and gradually increase the opening. The way to judge is by traffic flow. If you're getting a traffic jam, you can increase the opening. Wait until you have 7-8 frames covered before adding the second hive body. It doesn't do any good to put it on too early. You want them to have frames well drawn out in the first before adding a second story.Keep a steady supply of 1:1 syrup in the feeder. They will stop taking it when there is an adequate supply of nectar, but keep in mind that depending on the sources and weather it may fluctuate so it's good to leave feeders on as long as you need to. What's your location?