As far as feeding just get a plastic bin or something like that to feed in. The main reason for using the other container is so they don't get used to having food come into their enclosure. If this were the case, you'd end up sticking your hand in to clean the cage, and they'd think they were being fed and snag one of your fingers. After they've swallowed their prey, it's fine to move the snake back into its normal cage. By not handling the snake for a couple days, they mean no extensive handling. Handling it to put it away is fine.
As far as the heat pads, they're fine to use on their own without a heat lamp. For snakes belly heat for digestion is more important anyway.