Permissible and impermissible items of trade

Selling medicine to those who use it for haraam

Q: I am buying a pharmacy and am bringing in a colleague to work under me who specializes in increasing revenue. 

One of the ways he increases revenue is by selling codeine in bulk to a drug dealer at high prices who sells it on to addicts. My feeling is that this is haraam as its being sold to a haraam business who is then selling it to people to do haraam which causes suffering in the community. 

He also has contacts where he can sell the codeine in bulk to other pharmacies who may be selling it to drug addicts but we cannot verify this suspicion. Is this haraam? 

According to South African law, there is a quota of how much you can buy and sell in bulk because it is known to be an abused medicine but we cannot always verify what the intention is when selling large volumes to patients. 

I would truly value you advise on this.

Selling malic acid to breweries and to manufacture sweets

Q: I am interested in purchasing a company that manufactures malic acid. The acid is used in the manufacture of sweets to make them taste sour and also used in the manufacture of beer to give it a sour taste. 

The main customer base of the company is the breweries. 

Will it be permissible for me to purchase the company and maintain the same customer base?

Selling rizla

Q: I have noticed that my father has been selling filter/rolling paper (rizla) in bulk such as in large boxes to possible retail customers. I would just like to know whether it is permissible to sell such an item given the nature of its use?

Buying and selling fake goods

Q: I would like to know what is the masaail concerning fake goods. As a retailer stocking original goods (which does come with its price tag) finds others selling fake goods matching the originals at a much lower rate. Is it permissible to stock these goods? 

And what is the masaail concerning a person purchasing fake goods because the price is right.