Welcome to the wonderful world of Kindergarten! You're right it is a whole different ball game here, but one that I LOVE and will struggle leaving if my principal ever asks me. I'll answer each of your questions as to how I DO it, and hopefully enough people will answer that you can figure out what works best for you.
1) Daily 5, Daily 5, Daily 5!!!! Literacy Centers can be fun to make SOMETIMES but then they become a pain with little kids because you have to change them up constantly, and when you change them all the time there is never enough time to model them! Also, if you still decide to go through with Lit Centers, 30 minutes is far too long. We use to do 20 mins and that was pushing it by a few minutes. 30 minutes with the teacher will be hard for them to sit still and focused, let alone doing independent work for that long AND staying on track.
Daily 5 is like having 5 centers in your room all year that are very low maintenance once you set them up and build their stamina with each. Then you are free to call small groups or even individual students over as need be. The groups can be as short or as long as you need. (check out the Peony room)
2) Responsive Classroom works!!! Its an academic AND social approach to building a classroom community. Last year was my first year doing it and the children made the rules with me, they were problem solving their own peer conflicts, and the best thing??? NO behavior management charts!!!!! WOO HOOO no need to do treasure box at the end of the week... instead they become intrinsically motivated through personal goal setting. However, one thing with out being RC trained that you can do is make everything seem veryyyy exciting! They eat it righttt up
3) The theme in my room?? Organization! hahaha I don't do a theme in my room because then it becomes more about the cute store bought things I used to decorate it and less about the students work. As for changing my room, the boards stay the same because they are interactive all year. I have a Daily 5 board where they sign up for which activities they will do, a CAFE board where we add reading strategies we are working on, a Calendar board, a Math Daily 5 board where they pick which math station they want to go to and which games to play, a Math Strategy board we build during the year, and a library board that shows the procedures for filling up their book bins and how to put the books away.
The responsive classroom way of doing things is if you don't use it, lose it! So if you have something on your walls that you haven't used in 3 weeks, take it down. That's as much changing as I do.