Is it permissible for one to masturbate in order not to commit fornication?
This is called committing the milder of the two evils such as eating a carcass in fear of death, and this happens when committing fornication is very likely to occur.
Does touching one's wife invalidate ablution?
Touching the wife according to the Shafi'ee's doctrine invalidate husband's ablution. And Allah Knows Best.
What is the ruling of Sharia on uncovering Awrah before a female laser-hair-removal specialist to remove thick hair knowing that I`am engaged and feel embarrassed and this treatment is guaranteed and definitive?
Praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It is lawful for a Muslim woman to look at the body of another Muslim woman except what is between the navel and the knees. In addition, it is lawful to look at the whole body for treatment; however, having thick hair isn`t considered an illness. And Allah The Almighty Knows Best.
Is permissible to buy/sell with non-Muslim?
Yes buying/selling for a Muslim with non-Muslim is permissible as regards what is lawful.