Hi. I think it wants to tellyou that it becomes rare so much. . Because as you know, pandas are endangered and they're going to be extinct.

Hi For number 1 to 4, it's interchangeable and you can use both of them. But actually I can't understand number 5. And about number 6, I don't think that it's a complete sentence. so you should use Kindle instead of kindling. Because when you use kindling, you can't recognize what the tense is. Or you can say kindling by using one "are" before that.

         Hi   
   I think the best way to improve yourself is starting to talk to yourself in English.(face to face with yourself in the mirror) 
          
   I just want to tell you one more thing.
If you want to be better, the only way is to want it from your heart. Because if you really want it you will try for it. 
   Just one more thing. There is an app called "My wonder books". It's a kind of ebook that you can use it to improve your pronunciation and speaking and writing just by listening and paying attention to it. 
       
        I wish you everything good. 

Hi Hamid
I'm Saleh. 
I'm from Iran,  too.
If you want we can help each other to enhance our knowledge and English.