You have to use a double boiler so you don't burn what you are melting. If you don't have one, boil water in a big pot, then slowly melt the cheese, chocolate, etc in a smaller pot over the boiling water.
Yes absolutely! I've used a double boiler or the small "crock pot" that came as an extra with my large crock pot. the key is to watch the temperature and not let it get to a boil - just underneath a boil works fine.
You could get a pot, put some water in it, put a basin in the pot so that it's in the water but not touching the bottom of the pot, then put the chocolate in the basin and turn the burner on. Once the chocolate melts you can lower the fire so that it stays warm.
when my husband and I lived in London, we didn't have a fondue kit so we just used a regular pot. Kept the heat VERY VERY VERY low and ate right over the stovetop It was fun and cozy just the two of us. Now we have a fondue pot with the long forks and everything, but honestly the nights in London is what I remember!