First, its great that you are open to changing your approach. Second, realize that there will be a transition phase and it might take a bit of practice on everyone's part to get into the grove of a new approach to the world. If you are used to a much more authoritarian way of looking at the world, this takes some getting used to -- for both you and your children! Hang in there and give it a fair shot before deciding "this doesn't work".
Looking at your examples, is this all the same child? One of the things about GD is making sure you expectations and approach are appropriate to the age of the child. So I would have a different response to a "hissy fit" from a 2 YO (where it is developmentally normal and they are just learning to express themselves) and a 6 YO (where they have more abilities and self-control). But assuming this is all a 6 YO child...
Step 1 is always making sure you are setting your child up for success. So, for bedtime, do you have a good bedtime routine? Is it the right bedtime (driving by *his* sleep needs and schedule, not your desire to have him in bed for convenience)? Are all his basic needs met before lights out? Have you spent enough time with him? For us, the easiest thing was to stay with our children until they were asleep until they started to say they wanted to go to sleep on their own -- DS was about 9 and DD (6) still wants to cuddle until she is asleep. If that isn't a solution you are willing to try, then the gentle approach would be to quietly return child to bed after each time he gets up.
Taking food? Again, first make sure you aren't creating the problem. Is he getting enough snacks at the right times? If he is geniunely hungry, I would allow a nutritious snack. My basic rule is that after about 5 PM if they want a snack it would have to be something I would allow at the dinner table (so veggies, meat). Then if they eat less dinner I don't stress because they have already eaten some of their "dinner" at snack time. Remember that 1 hr. until dinner is a long time for a small tummy. And if your house is anything like ours, sometimes plans don't come together and dinner is late -- its not fair to expect your child to be hungry. If he's eating out of boredom, then suggest something for him to do (preferably outside and away from the kitchen). Explain why you don't want him to snack and offer alternatives (either different snack or different activity).
Hissy fits -- I just ignore them. I don't give in, but I also don't give them any attention. Again, this is assuming this is a school aged child, not a baby or toddler, that would be different. When *not* in the middle of a fit, talk about good ways to ask for things and encourage polite requests. DO pay attention and respond when your child asks for things in a nice way and/or first asks for your attention. Often a fit is our own fault because we said "just a minute" one time too many!
I guess I will update and hope someone wants to come on in and comment.
