Hi, there
The ideas you mentioned are excellent! I like them all, but due to the huge number of kids in one classroom (OMG, 45!!!), there should be some techniques in order to avoid your losing control over the little pupils there. Mainly in the first lesson, in which they don't know you and you don't know them. I'm sure there isn't a way for you to have a list with their names and pictures like we see in the movies LOL, so..... you will have to find a way to get acquainted with the names which is one of the most important things to be in control.
My main advice: avoid frontal activities in the first lesson. Unless you know their names, and you can tell at any moment things like "Johnny, Tom, Dina, stand up" and make a movement with your hands so they understand that they should stand up. But imagine doing this all the time, you will finish the lesson completely nuts.
Now seriously. I've taught little kids and some experience tells me that keeping them busy doing something is at the same time useful in terms of discipline, and can also teach something. If you still have time to prepare this activity I'm going to suggest to you, it might be a good idea to begin with.
Google the words "join the dots words generator online" and you will get to a worksheet tracing words through dot-to-dot generator (you will understand how to work there with the instructions and trying it out). You may prepare four names in each page, and after having them printed, you can cut them out and have strips with dotted names for them to trace. With a list of their names in your hand, you ask them in Chinese "Who is.....?" and hand him/her the strip of paper. Then they have to join the dots, colour and decorate their names. This activity takes some time, you can walk around the class which will help you to learn better where their places are and also their names.
To complete the remaining time, you can tell them that you are going to show them the letters of the alphabet. If you have flashcards with the letters, fine. If you don't, write them on the board: after you write A, ask pupils who have their names starting with A to raise there strips of paper. and so on. And IF there remains some time, finish the lesson with a game. Explain the rules: "If I say 'please' you do it. The one that does without the word 'please" must sit down. Tell everybody to stand up (always with movements) and give them very simple commands, like "stand up", "sit down". Put your finger on your eyes and tell them: "Please LOOK at me" pointing to yourself. Point at each object or something that you want them looking at and say "Look at...". The "sit down" and "stand up" , also "jump", are very exciting because you can all of a sudden say the word "stop!" without saying please and all the class will stop, so it's the end of the game!
I have lots and lots of ideas, don't hesitate asking me, I'll be very glad to help!

Good luck!
Syl
Syl's English Corner - Learn English and Have Fun
http://www.ginnegar.0catch.com