Concept of level design (level 2)

Hi, this is the continuation of the previous post I've posted.

Before this I had a question regarding opening and closing chest. I've managed to do that already and currently I'm working on level 2.

Now for some more questions. i manage to push the object and when the box fall it will hit the trigger and allowing the gate to open so the character can pull the switch to open the door below.

2.I also manage to allow the character to open and close the gate when the character step on and off the trigger.

3.the problem i having right now to make the floor switch have a spring characteristic.

"example: when a character walk on top of the floor switch it will slowly decend from it normal state.and when the character walk off the floor switch it will rise up again." is the link to elaborate more what im saying:

sorry if my english is bad..

You could eother animate the switch in an animation package and play it when the Character walks on in or probably more simply just lerp or slerp the vertical scale of the switch based on whether the player has triggered it by walking on it.

You can check out iTween, they have Sprint like movements...

For the spring joint...