Networking and some scripting question

Hello, i would like to ask a few questions. Please help. Thank you Pardon for the poor English and explanation.

1. Currently, i am working on a game and i name it as "Click && Match".As i am implementing in multiplayer mode, the game will go this way : Player 1 click A, B and form words, so what i want to do is in Player B's screen, they won't get to see A, B as this sets are already form by Player A. How do i go about doing it?? I am using the MasterServer to control everything.

2. Next, I want to make a blinking guiText, this question have been asked but not much response. http://answers.unity3d.com/questions/201953/blink-guitext-and-then-disappear-and-reappear.html

3. Thirdly, i got a main character walking around the scene. So when the main character go near the door or click on the door, i want it to trigger a scene, they need to finish the quest in order to open the door. Any ideas how could i get started with it.

Thank you :)