Ans 1: If you are a beginner, and want to start understanding the Quran, the best site is:http://www.understandquran.org
You can select one of many languages such as English, Urdu, Hindi, Bengali, etc.
I suggest you go through the short course, then the one called Basic course. The courses are downloadable.
There are other websites for Arabic in everyday use as well.http://www.madinaharabic.com/http://arabic.speak7.com/
Ans 2: There is indeed prohibition of wastage, particularly water. I cannot recall a Hadith, but even in wuddu and ghusl one is supposed to be economical.
Ans 3: If you have rolled up your sleeves, you should unroll them before the Salaah. If you are wearing a half sleeve shirt, there is nothing you can do. As for an absolute ban, I really do not know.
Ans 4: Here again it is best to ask a mufti. There are ultra-harsh muftis, and then there are more tolerant ones.
One does not really consume the rennet, which is very little. One consumes the cheese, but then the Muftis should be consulted.